[edit] History
For many years, a growing problem in astronomical research (as in other academic disciplines) was that the number of papers published in the major astronomical journals was increasing steadily, meaning astronomers were able to read less and less of the latest research findings. During the 1980s, astronomers saw that the nascent technologies which formed the basis of the Internet could eventually be used to build an electronic indexing system of astronomical research papers which would allow astronomers to keep abreast of a much greater range of research.
The first suggestion of a database of journal paper abstracts was made at a conference on Astronomy from Large Data-bases held in Garching bei München in 1987. Initial development of an electronic system for accessing astrophysical abstracts took place during the following two years; in 1991 discussions took place on how to integrate ADS with the SIMBAD database, containing all available catalog designations for objects outside the solar system, to create a system where astronomers could search for all the papers written about a given object.
An initial version of ADS, with a database consisting of 40 papers, was created as a proof of concept in 1988, and the ADS database was successfully connected with the SIMBAD database in the summer of 1993. The creators believed this was the first use of the Internet to allow simultaneous querying of transatlantic scientific databases. Until 1994, the service was available via proprietary network software, but it was transferred to the nascent World Wide Web early that year. The number of users of the service quadrupled in the five weeks following the introduction of the ADS web-based service.
At first, the journal articles available via ADS were scanned bitmaps created from the paper journals, but from 1995 onwards, the Astrophysical Journal began to publish an on-line edition, soon followed by the other main journals such as Astronomy and Astrophysics and the Monthly Notices of the Royal Astronomical Society. ADS provided links to these electronic editions from their first appearance. Since about 1995, the number of ADS users has doubled roughly every two years. ADS now has agreements with almost all astronomical journals, who supply abstracts. Scanned articles from as far back as the early 19th century are available via the service, which now contains over eight million documents. The service is distributed worldwide, with twelve mirror sites in twelve countries on five continents, with the database synchronized by means of weekly updates using rsync, a mirroring utility which allows updates to only the portions of the database which have changed. All updates are triggered centrally, but they initiate scripts at the mirror sites which "pull" updated data from the main ADS servers.
[edit] Data in the system
Papers are indexed within the database by their bibliographic record, containing the details of the journal they were published in and various associated metadata, such as author lists, references and citations. Originally this data was stored in ASCII format, but eventually the limitations of this encouraged the database maintainers to migrate all records to an XML (Extensible Markup Language) format in 2000. Bibliographic records are now stored as an XML element, with sub-elements for the various metadata.
Since the advent of online editions of journals, abstracts are loaded into the ADS on or before the publication date of articles, with the full journal text available to subscribers. Older articles have been scanned, and an abstract is created using optical character recognition software. Scanned articles from before about 1995 are usually available free, by agreement with the journal publishers.
Scanned articles are stored in TIFF format, at both medium and high resolution. The TIFF files are converted on demand into GIF files for on-screen viewing, and PDF or PostScript files for printing. The generated files are then cached to eliminate needlessly frequent regenerations for popular articles. As of 2000, ADS contained 250 GB of scans, which consisted of 1,128,955 article pages comprising 138,789 articles. By 2005 this had grown to 650 GB, and is expected to grow further, to about 900 GB by 2007. No further information has been published.
The database initially contained only astronomical references, but has now grown to incorporate three databases, covering astronomy (including planetary sciences and solar physics) references, physics (including instrumentation and geosciences) references, as well as preprints of scientific papers from arXiv. The astronomy database is by far the most advanced and its use accounts for about 85% of the total ADS usage. Articles are assigned to the different databases according to the subject rather than the journal they are published in, so that articles from any one journal might appear in all three subject databases. The separation of the databases allows searching in each discipline to be tailored, so that words can automatically be given different weight functions in different database searches, depending on how common they are in the relevant field.
Data in the preprint archive is updated daily from the arXiv, the main repository of physics and astronomy preprints. The advent of preprint servers has, like ADS, had a significant impact on the rate of astronomical research, as papers are often made available from preprint servers weeks or months before they are published in the journals. The incorporation of preprints from the arXiv into ADS means that the search engine can return the most current research available, with the caveat that preprints may not have been peer reviewed or proofread to the required standard for publication in the main journals. ADS's database links preprints with subsequently published articles wherever possible, so that citation and reference searches will return links to the journal article where the preprint was cited.
[edit] Software and hardware
The software runs on a system that was written specifically for it, allowing for extensive customization for astronomical needs that would not have been possible with general purpose database software. The scripts are designed to be as platform independent as possible, given the need to facilitate mirroring on different systems around the world, although the growing use of Linux as the operating system of choice within astronomy has led to increasing optimization of the scripts for installation on that platform.
The main ADS server is located at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts, and is a dual 64-bit X86 Intel server with two quad-core 3.0 GHz CPUs and 32 GB of RAM, running the CentOS 5.4 Linux distribution. Mirrors are located in Brazil, China, Chile, France, Germany, India, Indonesia, Japan, Russia, South Korea, United Kingdom, and the Ukraine.
[edit] Indexing
ADS currently receives abstracts or tables of contents from almost two hundred journal sources. The service may receive data referring to the same article from multiple sources, and creates one bibliographic reference based on the most accurate data from each source. The common use of TeX and LaTeX by almost all scientific journals greatly facilitates the incorporation of bibliographic data into the system in a standardized format, and importing HTML-coded web-based articles is also simple. ADS utilizes Perl scripts for importing, processing and standardizing bibliographic data.
The apparently mundane task of converting author names into a standard Surname, Initial format is actually one of the more difficult to automate, due to the wide variety of naming conventions around the world and the possibility that a given name such as Davis could be a first name, middle name or surname. The accurate conversion of names requires a detailed knowledge of the names of authors active in astronomy, and ADS maintains an extensive database of author names, which is also used in searching the database (see below).
For electronic articles, a list of the references given at the end of the article is easily extracted. For scanned articles, reference extraction relies on OCR. The reference database can then be "inverted" to list the citations for each paper in the database. Citation lists have been used in the past to identify popular articles missing from the database; mostly these were from before 1975 and have now been added to the system.
[edit] Coverage
The database now contains over eight million articles. In the cases of the major journals of astronomy (Astrophysical Journal, Astronomical Journal, Astronomy and Astrophysics, Publications of the Astronomical Society of the Pacific and the Monthly Notices of the Royal Astronomical Society), coverage is complete, with all issues indexed from number 1 to the present. These journals account for about two-thirds of the papers in the database, with the rest consisting of papers published in over 100 other journals from around the world.
While the database contains the complete contents of all the major journals and many minor ones as well, its coverage of references and citations is much less complete. References in and citations of articles in the major journals are fairly complete, but references such as "private communication", "in press" or "in preparation" cannot be matched, and author errors in reference listings also introduce potential errors. Astronomical papers may cite and be cited by articles in journals which fall outside the scope of ADS, such as chemistry, mathematics or biology journals.
[edit] Search engine
Since its inception, the ADS has developed a highly complex search engine to query the abstract and object databases. The search engine is tailor-made for searching astronomical abstracts, and the engine and its user interface assume that the user is well-versed in astronomy and able to interpret search results which are designed to return more than just the most relevant papers. The database can be queried for author names, astronomical object names, title words, and words in the abstract text, and results can be filtered according to a number of criteria. It works by first gathering synonyms and simplifying search terms as described above, and then generating an "inverted file", which is a list of all the documents matching each search term. The user-selected logic and filters are then applied to this inverted list to generate the final search results.
[edit] Author name queries
The system indexes author names by surname and initials, and accounts for the possible variations in spelling of names using a list of variations. This is common in the case of names including accents such as umlauts and transliterations from Arabic or Cyrillic script. An example of an entry in the author synonym list is:
[edit] Object name searches
The capability to search for papers on specific astronomical objects is one of ADS's most powerful tools. The system uses data from the SIMBAD, the NASA/IPAC Extragalactic Database, the International Astronomical Union Circulars and the Lunar and Planetary Institute to identify papers referring to a given object, and can also search by object position, listing papers which concern objects within a 10�arcminute radius of a given Right Ascension and Declination. These databases combine the many catalogue designations an object might have, so that a search for the Pleiades will also find papers which list the famous open cluster in Taurus under any of its other catalog designations or popular names, such as M45, the Seven Sisters or Melotte 22.
[edit] Title and abstract searches
The search engine first filters search terms in several ways. An M followed by a space or hyphen has the space or hyphen removed, so that searching for Messier catalogue objects is simplified and a user input of M45, M 45 or M-45 all result in the same query being executed; similarly, NGC designations and common search terms such as Shoemaker Levy and T Tauri are stripped of spaces. Unimportant words such as AT, OR and TO are stripped out, although in some cases case sensitivity is maintained, so that while and is ignored, And is converted to "Andromedae", and Her is converted to "Herculis", but her is ignored.
[edit] Synonym replacement
Once search terms have been pre-processed, the database is queried with the revised search term, as well as synonyms for it. As well as simple synonym replacement such as searching for both plural and singular forms, ADS also searches for a large number of specifically astronomical synonyms. For example, spectrograph and spectroscope have basically the same meaning, and in an astronomical context metallicity and abundance are also synonymous. ADS's synonym list was created manually, by grouping the list of words in the database according to similar meanings.
As well as English language synonyms, ADS also searches for English translations of foreign search terms and vice versa, so that a search for the French word soleil retrieves references to Sun, and papers in languages other than English can be returned by English search terms.
Synonym replacement can be disabled if required, so that a rare term which is a synonym of a much more common term (such as 'dateline' rather than 'date') can be searched for specifically.
[edit] Selection logic
The search engine allows selection logic both within fields and between fields. Search terms in each field can be combined with OR, AND, simple logic or Boolean logic, and the user can specify which fields must be matched in the search results. This allows complex searches to be built; for example, the user could search for papers concerning NGC 6543 OR NGC 7009, with the paper titles containing (radius OR velocity) AND NOT (abundance OR temperature).
[edit] Result filtering
Search results can be filtered according to a number of criteria, including specifying a range of years such as '1945 to 1975', '2000 to the present day' or 'before 1900', and what type of journal the article appears in – non-peer reviewed articles such as conference proceedings can be excluded or specifically searched for, or specific journals can be included in or excluded from the search.
[edit] Search results
Although it was conceived as a means of accessing abstracts and papers, ADS provides a substantial amount of ancillary information along with search results. For each abstract returned, links are provided to other papers in the database which are referenced, and which cite the paper, and a link is provided to a preprint, where one exists. The system also generates a link to 'also-read' articles – that is, those which have been most commonly accessed by those reading the article. In this way, an ADS user can determine which papers are of most interest to astronomers who are interested in the subject of a given paper.
Also returned are links to the SIMBAD and/or NASA Extragalactic Database object name databases, via which a user can quickly find out basic observational data about the objects analyzed in a paper, and find further papers on those objects.
[edit] Impact on astronomy
ADS is almost universally used as a research tool among astronomers, and there are several studies that have estimated quantitatively how much more efficient ADS has made astronomy; one estimated that ADS increased the efficiency of astronomical research by 333�full-time equivalent research years per year, and another found that in 2002 its effect was equivalent to 736�full-time researchers, or all the astronomical research done in France. ADS has allowed literature searches that would previously have taken days or weeks to carry out to be completed in seconds, and it is estimated that ADS has increased the readership and use of the astronomical literature by a factor of about three since its inception.
In monetary terms, this increase in efficiency represents a considerable amount. There are about 12,000�active astronomical researchers worldwide, so ADS is the equivalent of about 5% of the working population of astronomers. The global astronomical research budget is estimated at between 4,000 and 5,000�million USD, so the value of ADS to astronomy would be about 200–250�million USD annually. Its operating budget is a small fraction of this amount.
The great importance of ADS to astronomers has been recognized by the United Nations, the General Assembly of which has commended ADS on its work and success, particularly noting its importance to astronomers in the developing world, in reports of the United Nations Committee on the Peaceful Uses of Outer Space. A 2002 report by a visiting committee to the Center for Astrophysics, meanwhile, said that the service had "revolutionized the use of the astronomical literature", and was "probably the most valuable single contribution to astronomy research that the CfA has made in its lifetime".
[edit] Sociological studies using ADS
Because it is used almost universally by astronomers, ADS can reveal much about how astronomical research is distributed around the world. Most users access the system from institutes of higher education, whose IP address can easily be used to determine the user's geographical location. Studies reveal that the highest per-capita users of ADS are France and Netherlands-based astronomers, and while more developed countries (measured by GDP per capita) use the system more than less developed countries; the relationship between GDP per capita and ADS use is not linear. The range of ADS usage per capita far exceeds the range of GDPs per capita, and basic research carried out in a country, as measured by ADS usage, has been found to be proportional to the square of the country's GDP divided by its population.
ADS usage statistics also suggest that astronomers in more developed countries tend to be more productive than those in less developed countries. The amount of basic research carried out is proportional to the number of astronomers in a country multiplied by the GDP per capita. Statistics also imply that astronomers in European cultures carry out about three times as much research as those in Asian cultures, perhaps suggesting cultural differences in the importance attached to astronomical research.
ADS has also been used to show that the fraction of single-author astronomy papers has decreased substantially since 1975 and that astronomical papers with more than 50 authors have become more common since 1990.
[edit] Comparision to what the National Library of Medicine has done
The National Library of Medicine also has a free to users, supported by tax dollars, online database of scientific publications, PubMed.

Summary:
The Astrophysics Data System (usually referred to as ADS), developed by the National Aeronautics and Space Administration (NASA), is an online database of over eight million astronomy and physics papers from both peer reviewed and non-peer reviewed sources. Abstracts are available free online for almost all articles, and full scanned articles are available in Graphics Interchange Format (GIF) and Portable Document Format (PDF) for older articles. New articles have links to electronic versions hosted at the journal's webpage, but these are typically available only by subscription (which most astronomy research facilities have). It is managed by the Harvard–Smithsonian Center for Astrophysics.
ADS is a powerful research tool and has had a significant impact on the efficiency of astronomical research since it was launched in 1992. Literature searches that previously would have taken days or weeks can now be carried out in seconds via the ADS search engine, custom-built for astronomical needs. Studies have found that the benefit to astronomy of the ADS is equivalent to several hundred million US dollars annually, and the system is estimated to have tripled the readership of astronomical journals.
Use of ADS is almost universal among astronomers worldwide, and therefore ADS usage statistics can be used to analyze global trends in astronomical research. These studies have revealed that the amount of research an astronomer carries out is related to the per capita gross domestic product (GDP) of the country in which he/she is based, and that the number of astronomers in a country is proportional to the GDP of that country, so the total amount of research done in a country is proportional to the square of its GDP divided by its population.


[edit] Seasonal forecasts
On May�22, 2006, the National Oceanic and Atmospheric Administration (NOAA) released their forecasts for the 2006 Atlantic, East Pacific, and Central Pacific hurricane seasons. The Pacific season was expected to be hindered by the decades-long cycle that began in 1995, which generally increased wind shear across the basin. NOAA predicted a below-normal level of activity in the Eastern Pacific, with 12–16�named storms, of which 6–8 were expected to become hurricanes, and 1–3 expected to become major hurricanes. The Central Pacific basin was also expected to be below average, with only two to three tropical cyclones expected to form or cross into the area. They expected that neither El Niño nor La Niña would affect conditions significantly.
[edit] Storms
[edit] May and June
On May�15, the hurricane season began in the Eastern Pacific basin, which is the area of the northern Pacific Ocean east of 140ºW. Twelve days later, an area of disturbed weather developed into the first tropical depression of the season, about 190�mi (310�km) south of Acapulco, Mexico. It quickly intensified into a tropical storm, and upon doing so was named Aletta. The storm drifted northeastward toward the coast, bringing light rainfall before turning southward. Wind shear weakened the storm, and on May�31 Aletta dissipated about 200�mi (320�km) west-northwest of where it formed.
On June�1, the season began in the Central Pacific basin, which is the region between 140ºW and the International Dateline; however, no storms occurred in the basin until July. In the Eastern Pacific, Tropical Depression Two-E formed on June�3 about 145�mi (245�km) southwest of Zihuatanejo, Mexico. It tracked eastward and brought heavy rainfall to the coastline, with a report of about 11�inches (280�mm) in Acapulco. Land interaction weakened the depression, and it dissipated on June�5. No tropical storms developed in June in the basin, which was unusual compared to the average of two storms forming during the month. Since 1966, there have been only three other seasons in which a tropical storm did not form in June, these being 1969, 2004, and 2007.
[edit] July
After about a month of no storms, the basin became active in July. The first storm of the month was Hurricane Bud, which developed early on July�11 about 805�mi (1300�km) south of Cabo San Lucas. Moving west-northwestward, it encountered conditions for quick strengthening, and within 24�hours of forming it attained hurricane status. Bud continued strengthening, reaching major hurricane status, or Category�3 status on the Saffir-Simpson scale, and peak winds of 125�mph (205�km/h) on July�13. Thereafter, cooler waters and stable air caused the hurricane to quickly weaken. On July�14, Bud weakened to tropical storm status, and two days later it degenerated into a remnant low pressure area. The remnants of Bud dissipated on July�17 about 750�mi (1210�km) east-southeast of Hawaii.
One day after Bud formed, a tropical disturbance organized into a tropical depression about 290�mi (465�km) off the coast of Mexico, which would later become Hurricane Carlotta. A large cyclone, its outer rainbands brushed the coastline of Mexico, as it steadily intensified to reach tropical storm and later hurricane status within 30�hours of forming. Outflow from Hurricane Bud prevented Carlotta from strengthening much further, though for a period of about 60�hours it fluctuated between strong tropical storm status and minimal hurricane status. Cooler waters weakened the storm, and on July�16 Carlotta degenerated into a remnant low. Its low-level circulation persisted for three days before dissipating.
As the previous two storms were dissipating, a new tropical depression formed off the southwest coast of Mexico on July�16, which would later become Hurricane Daniel. It moved westward, gradually intensifying under favorable conditions. On July�22, it attained peak winds of 150�mph (240�km/h), a Category�4 on the Saffir-Simpson scale and making Daniel the strongest hurricane during the season in the NHC area of responsibility. Maintaining Category�4 status for about three days, the hurricane subsequently weakened quickly due to cooler waters. Daniel was briefly forecast to move through the Hawaiian Islands as a tropical storm; however, the storm continued to weaken, degenerating into a remnant low on July�27 about 800�mi (1290�km) east-southeast of Hilo, Hawaii. Its remnants brought moderate rainfall to the region, though no damage or deaths were reported.
Another tropical depression formed off the coast of Mexico on July�21. It tracked northward toward the coast, strengthening into Tropical Storm Emilia and attaining peak winds of 65�mph (105�km/h). It briefly developed an eye, though weakened due to increased wind shear as it turned away from the coast. Emilia later turned to the north, restrengthening to its peak intensity before weakening and paralleling the coastline of the Baja California peninsula. After dropping moderate rainfall along the peninsula, it weakened further as it turned out to sea, and on July�27 degenerated into a remnant low.
The final storm of the month formed on July�31 from a tropical wave, well to the southwest of Mexico. It maintained a steady westward track throughout its duration, and quickly intensified into Tropical Storm Fabio. On August�1 it attained peak winds of 50�mph (85�km/h), but subsequently began gradually weakening due to wind shear. Fabio degenerated into a remnant low on August�4, and a few days later brought locally heavy rainfall to Hawaii.
[edit] August
Within the basin, more tropical cyclones developed in August than in any other month. The first storm of the month was Tropical Storm Gilma, which in terms of winds was tied with Rosa for the weakest named storm of the season. Gilma developed on August�1 off the southwest coast of Mexico, attaining peak winds of 40�mph (65�km/h). The storm was disorganized due to persistent wind shear, which prevented further strengthening. On August�5 the cyclone dissipated without ever having affected land.
After a period of inactivity lasting a week and a half, a tropical depression formed southwest of Mexico on August�15. It tracked generally west-northwestward for its entire duration, eventually becoming Hurricane Hector. On August�18, it attained peak winds of 110�mph (175�km/h), before gradually weakening due to cooler waters. Weakening to a tropical storm on August�20, it later turned sharply to the west, degenerating into a remnant low on August�23 and dissipating the next day without affecting land.
The strongest hurricane of the season was Hurricane Ioke, which formed on August�20 far to the south of Hawaii. It was the first central Pacific named storm since Hurricane Huko in 2002. Encountering warm waters and little wind shear, and maintaining well-defined outflow, Ioke intensified from a tropical depression to Category�4 status on the Saffir-Simpson scale within 48�hours. Late on August�22 it rapidly weakened to Category�2 status before crossing over Johnston Atoll, where 12�people rode out the storm in a hurricane-proof bunker. Two days later, favorable conditions again allowed for rapid strengthening, and Ioke attained Category�5 status on August�25 before crossing the International Date Line. As it continued westward its intensity fluctuated, and on August�31 it passed near Wake Island with winds of 155�mph (249�km/h). Ioke gradually weakened as it turned northwestward and northward, and by September�6 transitioned into an extratropical cyclone. The remnants of Ioke accelerated northeastward and ultimately crossed into Alaska.
On August�21 shortly after the previous storm formed, Hurricane Ileana developed off the southwest coast of Mexico. It generally paralleled the coastline throughout its duration, ultimately reaching peak winds of 120�mph (195�km/h) before weakening. Around the time of peak intensity, the hurricane passed near Socorro Island, where it produced hurricane-force wind gusts. On August�27, Ileana degenerated into a remnant low, and two days later dissipated well offshore.
The next tropical depression, which would eventually become Hurricane John, formed on August�28 about 250�mi (400�km) off the coast of Mexico. With favorable environmental conditions, the system quickly organized, becoming a hurricane within 36�hours of forming. Hurricane John continued rapid intensification and reached peak winds of 135�mph (215�km/h) on August�30 while just off the Mexican coast. Land interaction weakened the hurricane, and still tracking northwestward it struck the eastern portion of the Baja California peninsula on September�2 as a Category�2 hurricane. John dissipated on September�4, though its remnants brought rainfall to the southwest United States.
The last storm to develop in August was Hurricane Kristy, which formed on August�30 about 935�mi (1505�km) west-northwest of Hurricane John. It initially tracked northwestward, reaching peak winds of 80�mph (130�km/h) within 36�hours of forming. Outflow from Hurricane John caused Kristy to weaken, and at the same time, the storm's motion became nearly stationary as steering currents collapsed. On September�2 it turned to a southeast drift, and degenerated into a tropical depression around the same time. Kristy later turned to the west, oscillating between tropical depression and tropical storm status until dissipating on September�9.
[edit] September
Hurricane Lane developed from a tropical wave on September�13 to the south of Mexico. It moved northwestward parallel to the coast of Mexico, and steadily intensified in a favorable environment. After turning to the northeast Lane attained peak winds of 125�mph (205�km/h), and made landfall in the Mexican state of Sinaloa at peak strength. It rapidly weakened and dissipated on September�17, and later brought precipitation to southern Texas.
An area of disturbed weather associated with the Intertropical Convergence Zone spawned a tropical depression on September�16 off the coast of Mexico. Despite being disorganized, it quickly strengthened into Tropical Storm Miriam. The storm was sheared throughout its duration, and after encountering cooler waters Miriam dissipated on September�18 near the Baja California peninsula.
On September�18, an area of disturbed weather in the central Pacific became sufficiently organized and was designated Tropical Depression Two-C. Vertical wind shear caused the depression to weaken into a remnant low on September�20, it never having attained tropical storm status. The depression was initially thought to be a regeneration of earlier Hurricane Kristy.
On September�26, another area of disturbed weather in the Central Pacific near the International Date Line became organized and was designated Tropical Depression Three-C. However, wind shear and the presence of dry air to the west inhibited further development, and the system dissipated 12�hours later; at around the same time, the system crossed into the Western Pacific.
[edit] October
The first cyclone to develop in the month of October was Tropical Storm Norman, which formed well off the coast of Mexico on October�9. It quickly reached peak winds of 50�mph (85�km/h), though almost as quickly the cyclone degenerated into a remnant low due to wind shear. Its remnants turned to the east, and on October�15 regenerated into a tropical cyclone just off the coast of Mexico after merging with another disturbance. Norman quickly dissipated as unfavorable conditions returned, although it brought heavy rainfall to the Mexican coastline.
Tropical Storm Olivia formed on October�9 about 700�mi (1120�km) west of Norman. Tracking northeastward and attaining tropical storm status, it failed to strengthen significantly due to wind shear. Olivia weakened to tropical depression status on October�11, and turning to the east-southeast degenerated into a remnant low two days later. Its remnants were later absorbed by a larger disturbance that included the remnants of Norman.
The final cyclone to develop within the CPHC area of responsibility was Tropical Depression Four-C, which formed on October�13 to the southwest of Hawaii. Within 24�hours of forming, it degenerated into a remnant disturbance due to unfavorable wind shear. Moisture from the depression contributed to heavy rainfall in Hawaii.
The strongest hurricane during the month was Hurricane Paul. Forming on October�21, it did not strengthen much initially due to the presence of wind shear. However, a decrease in shear allowed Paul to strengthen rapidly, and in a 24-hour period it developed from a moderate tropical storm to a 105�mph (170�km/h) hurricane, its peak intensity. By that time, it had turned northeastward and entered an unfavorable environment, which caused Paul to steadily weaken to tropical storm status. After passing south of the Baja California peninsula it deteriorated to tropical depression status and moved ashore in northwestern Sinaloa.
On October�26 shortly after Paul dissipated, another tropical depression formed off the southwest coast of Mexico. Moving southwestward, it encountered unfavorable wind shear, which prevented strengthening. On October�28 it degenerated into a remnant low, and the next day dissipated without affecting land.
[edit] Unclassified storm
An extratropical storm persisted in the extreme northern central Pacific Ocean in late October. It drifted over unusually warm waters up to 3.6°F (2°C) above normal, and gradually developed convection near the center. By November�2, QuikSCAT satellite suggested the system attained winds of up to 60�mph (95�km/h) about 900�mi (1450�km) west of Oregon. The system also developed an eye and an eyewall. The cyclone tracked northeastward as it gradually weakened, and dissipated on November�4. NASA considered the cyclone to be a subtropical storm. However, as it formed outside of the territory of any monitoring organization, it was not named. Operationally, the United States Navy treated the system as a tropical disturbance, numbered 91C.
[edit] November
Tropical activity within the basin in November�2006 was the most active on record, based on the Accumulated Cyclone Energy (ACE) Index. Three tropical cyclones formed, of which two became tropical storms; only one other season on record, 1966, produced two tropical storms in the month of November. The first storm of the month was Tropical Storm Rosa, which formed on November�8 as a tropical depression off the southwest coast of Mexico. Immediate development was hampered by wind shear, although an increase in thunderstorms on November�9 brought the depression to tropical storm status. Continued shear prevented intensification, and Rosa dissipated on November�10. Rosa was the first Eastern Pacific tropical storm in November since another storm named Rosa in the 2000 season.
On November�11, another tropical depression formed off the coast of Mexico, about 450�mi (720�km) west-southwest of where Rosa dissipated the previous day. Similar to Rosa, it developed within an environment with unfavorable wind shear, but failed to intensify beyond tropical depression status. About 18�hours after it formed the depression degenerated into a trough.
The final storm of the season was Hurricane Sergio, which was both the strongest and longest-lived November Pacific hurricane on record. It formed on November�13 about 460�mi (740�km) south of Manzanillo, Colima, and steadily intensified while tracking southeastward. It reached peak winds of 110�mph (175�km/h) on November�15, and subsequently began to weaken due to increased wind shear as it turned to the north. Sergio later turned to the west, remaining well off the coast of Mexico, and dissipated on November�20 about 320�mi (515�km) west-northwest of it originally formed. The storm brought light rainfall to the Mexican coastline, though no major effects were reported.
[edit] Impact
During the season, tropical cyclones collectively caused 14�fatalities and $355�million in damage (2006�USD).[nb 1]
With its long coastline, the country of Mexico was affected by ten of the cyclones during the season, including four that made landfall. Of the six storms that affected Mexico but did not strike the country, the first was Tropical Storm Aletta, the first storm of the season, which brought light rainfall and caused minor damage. The next tropical depression of the season produced heavy rainfall in the Acapulco area while remaining offshore; mudslides and flooding were reported, and 72�people were forced to leave their homes. In July, Hurricane Carlotta brushed the coastline with light rainfall. When Tropical Storm Emilia passed just off the coast of Baja California, it brought moderate precipitation which caused minor flooding and damage around Cabo San Lucas. Heavy surf from Hurricane Ileana killed a man near Cabo San Lucas. The last storm of the season, Hurricane Sergio, produced light rainfall along the coast while remaining well offshore.
Mexico was struck by four tropical cyclones in 2006, all along the Pacific coast. The first was Hurricane John, which made landfall near the southern tip of the Baja California peninsula on September�1. Earlier, it produced flooding and high surf near Acapulco while paralleling the coastline, and later the hurricane damaged or destroyed at least 450�homes in the Baja California peninsula. Hurricane John was the wettest tropical cyclone of the year in Mexico, dropping 17.7�in (449�mm) of rainfall. Five people were killed, and damage in Mexico amounted to $663�million (2006�MXN, $60.8�million 2006�USD). Hurricane Lane moved ashore in the state of Sinaloa as a Category�3 hurricane on the Saffir-Simpson scale, which was the strongest landfall during the season. Paralleling the coastline a short distance offshore, the hurricane dropped heavy rainfall, causing flooding and mudslides which resulted in four fatalities. Hurricane Lane affected 4,320�houses, and a total of 19,200�mi (30,000�km) of roads and highways were damaged to some degree. Monetary damage amounted to about $2.2�billion (2006�MXN, $203�million 2006�USD) in damage in the country. In early October, former Tropical Storm Norman passed near or over southwestern Mexico, destroying 20�houses and leaving 20�villages without power. Later, former Hurricane Paul caused four deaths, two of which from rough seas and two from drowning in a flooded river. The storm damaged 5,000�houses, and monetary damage totaled more than $35�million (2006�MXN, $3.2�million 2006�USD).
Three of the cyclones that affected Mexico also impacted the southwestern United States. Moisture from Tropical Storm Emilia produced thunderstorms in Arizona which caused flooding, and in southern California its rainfall assisted firefighters in combating a wildfire. The remnants of Hurricane John produced moisture across much of the southwestern United States, causing mudslides in California, light rainfall in Arizona, overflowed rivers in New Mexico, and up to 8�in (200�mm) of rainfall in Texas. In western Texas, the precipitation was beneficial in some areas but damaging in others, causing flooded roads and washouts. The remnants of Hurricane Lane also produced rainfall in Texas.
Four tropical cyclones affected the U.S. state of Hawaii, all of which were the remnants of former tropical cyclones. Moisture from Hurricane Bud produced light rainfall in east-facing slopes of the island chain. Former Hurricane Daniel produced up to 5�in (125�mm) of rainfall in the state, though no significant impact was reported. The remnants of Tropical Storm Fabio contributed to heavy rainfall, peaking at 15.08�in (383�mm) on Mount Waiʻaleʻale on the island of Kauai; the rainfall caused river and roadway flooding, but little damage. Moisture from Tropical Depression Four-C in October contributed to heavy rainfall on the island of Hawaii.
The strongest hurricane of the season was Hurricane Ioke, which reached Category 5 status in the central Pacific Ocean. It first affected the uninhabited Johnston Atoll, although when Ioke struck there was a crew of 12�people taking shelter on the island. Hurricane force winds affected the landmass, powerful enough to knock down trees. In the western Pacific Ocean after being re-classified as a typhoon, Ioke passed near Wake Island, forcing the first full-scale evacuation of the island since a typhoon in 1967. The combination of strong winds and a powerful storm surge damaged 70% of the buildings on the island, many with moderate roof damage. Destruction on the island was estimated at $88�million (2006�USD). Later, the storm passed near the Japanese island of Minami Torishima, which was also fully evacuated; facilities on the island were damaged, although it was repaired and fully operational within three weeks after the storm. The remnants of Ioke later brought hurricane force wind gusts to southwestern Alaska.
[edit] Season effects
This is a table of the storms in 2006 and their landfall(s), if any; the table does not include storms that did not make landfall, which is defined as the center of the storm moving over a landmass. Deaths in parentheses are additional and indirect (an example of an indirect death would be a traffic accident), but are still storm-related. Damage and deaths include totals while the storm was extratropical or a wave or low.
[edit] Storm names
The following names were used for named storms that formed in the northeast Pacific in 2006. This is the same list that was used in the 2000 season. There were no names retired from the northeast Pacific list. Therefore, the same list will be reused in the 2012 season.
Storms that formed in the central Pacific are given names from a sequential list; in 2006, the name Ioke was used from this list, the first time a name from the Central Pacific list had been used since the 2002 season.
[edit] Retirement
The name Ioke was retired from the north-central Pacific list by the WMO in the spring of 2007 and replaced with Iopa. During the 61st Interdepartmental Hurricane Conference, the Hawaii State Civil Defense requested the retirement of the name Daniel, citing that the storm had become memorable due to threat or damage. However, the request was denied, as the name remains on the tropical cyclone naming list.

Summary:
The 2006 Pacific hurricane season was the most active since 2000, which also produced 19�tropical storms or hurricanes. Eighteen developed within the National Hurricane Center (NHC) area of warning responsibility, which is east of 140°W, and one storm formed between 140°W and the International Date Line, which is under the jurisdiction of the Central Pacific Hurricane Center (CPHC). Of the 19�total storms, eleven became hurricanes, of which six attained major hurricane status. Within the NHC portion of the basin, the season officially began on May�15, and in the CPHC portion, it started on June�1; the season officially ended on November�30. These dates conventionally delimit the period of each year when most tropical cyclones form in the eastern Pacific basin.
The strongest storm of the season was Hurricane Ioke, which reached Category 5 status on the Saffir-Simpson scale in the central Pacific Ocean; Ioke passed near Johnston Atoll and later Wake Island, where it caused heavy damage but no deaths. The deadliest storm of the season was Hurricane John, which killed six people after striking the Baja California Peninsula, and the costliest storm was Hurricane Lane, which caused $203�million in damage in southwestern Mexico.
Seasonal activity began on May�27 when Tropical Storm Aletta formed off the southwest coast of Mexico. No storms formed in June, though the season became active in July when five named storms developed, including Hurricane Daniel which was the second strongest storm of the season. During August, Hurricanes Ioke and John formed, as well as four other storms. September was a relatively quiet month with two storms, of which one was Hurricane Lane. Three storms developed in October and two formed in November; this marked the first time on record when more than one tropical storm developed in the basin during the month of November.


[edit] Early history
Humans may have visited Yosemite as long ago as 8,000 to 10,000 years ago. Vegetation and game in the region was similar to what is there today by the time people started to settle Yosemite Valley 3000 years ago. Western slopes of the Sierra Nevada had acorns, deer and salmon while the eastern Sierra had pinyon nuts and obsidian. Native American groups traveled between these two areas to trade and raid.
Archaeologists divide the pre-Euro-American contact period of the region into three cultural phases. The Crane Flat phase lasted from 1000�BCE to the year 500. Hunting with the atl atl and use of grinding stones occurred during this period. The Tarmarack phase lasted from the year 500 to 1200 and is marked by a shift to using smaller rock points, which indicates development and use of the bow and arrow. Acorns also become a part of the diet at this time. The Mariposa phase lasted from 1200 until contact with Euro-Americans. Trade between tribes became more widespread during this period and the diet continued to improve. Miwok, Monos and Shoshonean-speaking tribes visited the area to trade. A major trading route went over Mono Pass and through Bloody Canyon to Mono Lake in Eastern Californian.
In the 11th or 12th century a band of indigenous people who called the valley that provided them with nuts, berries, and small game Ahwahnee (meaning "place of a gaping mouth") moved into the valley. They called themselves the Ah-wah-ne-chee (meaning dwellers in Ahwahnee).
Like humans before and since, the Ahwahnechee changed the Valley to suit their needs. Since the band depended upon acorns for 60% of their diet, they burned vegetation on the Valley floor, which favored California Black Oak - an acorn-producing tree. Fire management also expanded meadows and reduced brush within woodlands, thus making ambush by invading tribes difficult.
Displaced Native Americans from the coast of California moved to the Sierra Nevada in the early to mid-19th century. They brought their experiences with Spanish food, technology, and clothing as they joined tribes in the mountains. Together they raided ranchos on the coast and drove herds of horses to the Sierra, where horse meat became a major new food source. The Shoshonean-speaking Monache moved from eastern deserts into the southern Sierra in the last three to five hundred years.
[edit] Exploration by Europeans
Significant debate still surrounds the issue of who the first non-indigenous person to see the Valley was. Spanish missions and colonies existed along the coast of California but no Spanish explorers visited the Sierra Nevada. A group led by American fur trapper Jedediah Smith became the first Euro-Americans to cross the Sierra Nevada. They crossed at Ebbetts Pass, north of the Yosemite area in May 1827.
In the autumn of 1833, a group led by Joseph Reddeford Walker may have seen Yosemite Valley but did not enter it. Walker approached a valley rim as he led his party of trappers across the Sierra Nevada. A member of the party, Zenas Leonard, wrote in his journal that streams from the valley rim dropped "... from one lofty precipice to another, until they are exhausted in rain below. Some of these precipices appeared to us to be more than a mile high." In 1839 a print shop fire in Philadelphia destroyed journals related to the Walker group. He and his party also likely happened upon either the Tuolumne or Merced Groves of Giant Sequoia, becoming the first known non-indigenous people to see the giant trees.
The part of the Sierra Nevada where the park is located was long considered to be a physical barrier to non-indigenous settlers, traders, trappers, and travelers. That status changed, in 1848, due to the discovery of gold in the foothills west of the range in the California Gold Rush. Travel and trade activity dramatically increased in the area, competing with the local Native Americans and destroying resources they depended upon. Disease from the newcommers spread rapidly through Native American populations and extermination of native culture became a policy of the United States Government, which obtained California from Mexico in 1848.
The first reliable sighting of the Valley by a non-indigenous person occurred on October 18, 1849 by William P. Abrams and a companion. Abrams accurately described some landmarks but it is not known for sure whether or not he or his companion actually entered the Valley. In 1850, Joseph Screech became the first confirmed non-indigenous person to enter Hetch Hetchy Valley. He settled there, and noted that the Paiutes inhabited Hetch Hetchy before the coming of the Europeans.
The first intentional and systematic exploration of any part of the Yosemite area backcountry was conducted in 1855 by the surveying crew of Allexey W. Von Schmidt, as part of the Public Land Survey System. Von Schmidt's charge was to establish the Mount Diablo Base Line from the initial point at Mount Diablo east across the Sierra Nevada, preliminary to the General Land Office (GLO) rectangular survey in California and Nevada. This line passes through Tuolumne Meadows and very near the summit of Mount Dana, (although Von Schmidt, for unknown reasons, surveyed his line 5 to 6�miles (9.7�km) south of the actual line, which was not surveyed until around 1880). This survey was the first crossing of the Sierra Nevada that did not follow established trails or the natural routes suggested by topography. In 1863–67, the California Geological Survey surveyed parts of Yosemite's high country and the boundary of the new state park. From 1879 to 1883 large areas of the park were contracted for survey by GLO contract surveyors. However, the individual contracted for the largest area, one S.A. Hanson, was associated with the Benson Syndicate, and he combined actual with probably fabricated surveys. In 1878–79 topographic surveys performed by Lieutenant Montgomery Macomb, under George M Wheeler's Surveys West of the 100th Meridian, made use of various peaks in the high country to connect with Wheeler's extensive surveys further east, north and south.
[edit] Mariposa Wars and legacy
A mining camp was established in 1849 at Big Oak Flat on tributaries of the Tuolumne River. James Savage was running a mining operation and trading camp on the Merced River 10�miles (16�km) west of Yosemite Valley by 1850. He ran a similar camp near Mariposa. Both camps were raided by Native Americans in December 1850. The raiders retreated back in the mountains.
In 1851 the Mariposa Battalion was created under the authority of the Governor of California to put an end to these raids and starting the Mariposa Wars. James Savage led the Battalion into Yosemite Valley in 1851 while in pursuit of around 200 Ahwaneechees led by Chief Tenaya. On Thursday March 27 of that year the company of 50 to 60 men reached what is now called Old Inspiration Point and saw the major features of the Valley laid out before them (they named the overlook Mt. Beatitude). Attached to Savage's unit was Dr. Lafayette Bunnell, the company physician who later wrote about his awestruck impressions of the valley in The Discovery of the Yosemite.
While camped at Bridalveil Meadow Bunnell suggested that the Valley be named '"Yo-sem-ity", after what the surrounding Sierra Miwok tribes, who feared the Yosemite Valley tribe, called them. At the time, Savage, who spoke some native dialects, translated this as "full-grown grizzly bear". Later translations found that the actual term, while possibly derived or at least confused with the similar uzumati or uhumati (meaning 'grizzly bear'), was in fact a Southern Sierra Miwok word Yohhe'meti meaning "they are killers". The name stuck even though the tribe they named the valley after called themselves Ahwahnechee.
Bunnell went on to name many other local topographic features on the same trip. Others in the company were also moved by what they saw and recounted their journey to friends and family after they returned, increasing interest in the Valley and surrounding area. Bunnell soon after drafted an article about the trip, but destroyed it when a newspaper correspondent in San Francisco suggested cutting his 1500�foot (460�m) height estimate for the Valley walls in half (the walls are in fact twice the height that Bunnell surmised). So the first published account of the Valley was written by Lt. Tredwell Moore for the January 20, 1854 issue of the Mariposa Chronicle. The modern spelling of Yosemite was established by that article.
Chief Tenaya and his band were eventually captured and their village burned, fulfilling a prophecy an old and dying medicine man gave Tenaya many years before. The Ahwahnechee were escorted by their captor Captain John Bowling to the Fresno River Reservation. Life on the reservation was unpleasant and the Ahwahneechee longed for their valley, prompting reservation officials to allow Tenaya and some of his band to return on their own recognizance in winter.
A group of eight miners entered the Valley in the Spring of 1852 and were allegedly attacked by Tenaya's warriors, with two of the miners being killed. A second battalion was organized, and executed six Ahwahneechee under the direction of Lt. Moore. Tenaya's band fled the Valley and sought refuge with the Mono, his mother's tribe. In Summer or early Fall of 1853, the Ahwahneechee apparently returned to the Valley, but later betrayed the hospitality of their former Mono hosts by stealing some horses that the Mono had taken from non-indigenous ranchers. In return the Monos tracked down and killed many of the remaining Ahwahneechee, including Tenaya. Tenaya Lake is named after the fallen chief. Hostilities then subsided, and by the mid 1850s local non-indigenous residents started to befriend Native Americans living in the Yosemite area.
Mono Paiutes were the only group that kept returning to the Valley on a regular basis. They lived in established native villages in the Valley into the early 20th century. As older tribe members died, younger ones tended to favor non-traditional housing provided by the National Park Service. A few Paiute and Miwok families still live in the Valley and are employed by the Park Service. A reconstructed "Indian Village of Ahwahnee" is now located behind the Yosemite Museum, which is next to the Yosemite Valley Visitor Center. The museum has exhibits that interpret the cultural history of Yosemite's indigenous residents from 1850 to the present. In addition, the museum has regularly scheduled demonstrations of basket-weaving, beadwork, and traditional games by Native American presenters.
[edit] Popularization, exploitation, and protection
[edit] Artists, photographers, and the first tourists
Forty-eight people ventured into Yosemite Valley in 1855. Among these were San Francisco writer James Mason Hutchings and artist Thomas Ayres. After returning to Mariposa Hutchings wrote an article about his experience which appeared in the July 12, 1855 issue of the Mariposa Gazette and was later published in various forms nationally. , Ayres' sketch of Yosemite Falls was published in fall that year, and four of his drawings were presented in the lead article of the July 1856 and initial issue of Hutchings' Illustrated California Magazine. These were the first known accurate pictures of Yosemite Valley. Ayres returned in 1856 and visited Tuolumne Meadows in the area's high country. His highly-detailed but angularly-exaggerated artwork and his written accounts were published nationally. An art exhibition of his drawings was later held in New York City.
Hutchings brought photographer Charles Leander Weed to the Valley in 1859. Weed took the first photographs of the Valley's features, and a September exhibition in San Francisco presented them to the public. Hutchings published four installments of "The Great Yo-semite Valley" from October 1859 to March 1860 in his magazine. A book by Hutchings titled Scenes of Wonder and Curiosity in California collected these articles and the book stayed in print well into the 1870s.
Stanford University mechanical engineering student Arthur Clarence Pillsbury arrived in Yosemite for the first time by bicycle in 1895. The young man fell in love with Yosemite and in 1897 bought a studio there. He visited Yosemite many times and photographed Muir, Galen Clark, George Fiske, and Teddy Roosevelt. These photos were published as postcards by the Pillsbury Picture Company. Pillsbury had begun producing postcards with his photos as soon as this innovative form of communication was authorized by Congress in 1898. His many nature films, eventually shown in theaters as well as in schools, clubs and for his lecture tours awakened the public to the need for conservation in the wake of Muir's death in 1914.
Photographer Ansel Adams, who made his first trip to Yosemite in 1916, was famous for his photographs of Yosemite in the 1920s and 30s. He willed the originals of his Yosemite photos to the Yosemite Park Association, and visitors can still buy direct prints from his original negatives. The studio in which prints are sold was established in 1902 by artist Harry Cassie Best. Carleton Watkins exhibited his 17x22-inch Yosemite views at the 1867 Paris International Exposition.
In 1856, Milton and Houston Mann (2 of 42 tourists to visit the valley the year before) finished a toll road to the Valley that traveled up the South Fork of the Merced River. Before they were bought out by Mariposa County they charged the then large sum of two dollars per person. Under county control the road was free.
Wawona was an indigenous encampment in what is now the southwestern part of the park. Settler Galen Clark discovered the Mariposa Grove of Giant Sequoia in Wawona in 1856; a year later he completed a bridge over the South Fork Merced in Wawona for traffic inbound to the Valley. Clark also provided a way station for tourists traveling on the road that the Mann brothers built to the Valley. Simple lodgings, later called the Lower Hotel, were completed soon afterward; Upper Hotel (later renamed Hutchings House and now known as Cedar Cottage) was opened in 1858. In 1879, the more substantial Wawona Hotel was built to serve tourists visiting the nearby Grove and those on their way to the Valley (at the time, it took 8 hours to travel from Wawona to the Valley via stage). The Washburns, owners of the hotel, bought Clark's land and covered the bridge he built. A year before the hotel was completed, A. Harris built the first public campground in Yosemite. As tourism increased, the number of trails and hotels also increased.
[edit] Early protection efforts and the state park
Visitation and interest in Yosemite continued through the American Civil War. A Unitarian minister named Thomas Starr King visited the Valley in 1860 and saw some of the negative effects that homesteading and commercial activity were having on the area. Six travel letters by King were published in the Boston Evening Transcript in 1860 and 1861 (Oliver Wendell Holmes and John Greenleaf Whittier read and commented on them). King went on to become the first person with a nationally-recognized voice to call for a public Yosemite park. Frederick Law Olmsted, the United States' most widely respected landscape architect, became interested by Kings' warnings and visited Yosemite Valley and the Mariposa Grove in 1863.
Pressure by King and Olmstead, photographs by famed photographer Carleton Watkins, and geologic data from the 1863 Geological Survey of California prompted legislators to take notice. Senator John Conness of California introduced a Park bill in 1864 to the United States Senate that would cede Yosemite Valley and the Mariposa Grove to California.
The uncontroversial bill passed both houses of the United States Congress and was signed by President Abraham Lincoln on June 30, 1864, creating the Yosemite Grant as a public trust. Yosemite Valley and the Mariposa Grove were ceded to California as a state park for "public use, resort and recreation." A board of Yosemite commissioners was proclaimed by the state's governor September that year, but the body did not convene until 1866 (with Frederick Law Olmsted as chairman).
Galen Clark was appointed by the commission as the park's first guardian, but neither Clark nor the commissioners had the authority to evict homesteaders, starting an 11 year struggle. Josiah Whitney, the first director of the California Geological Survey, lamented that Yosemite Valley may become like what Niagara Falls was at the time�— a tourist trap where proprietary interests place tolls on every bridge, path, trail, and viewpoint. Hutchings was one of a small group that wanted homesteading rights on 160�acres (65�ha) of the valley floor. The issue was not settled until 1875 when the land holdings of Hutchings and three others were invalidated. A State grant of $24,000 for improvements Hutchings made to Upper Hotel helped compensate for his loss. Two years after losing his land, Hutchings published a second Yosemite guide, Hutchings' Tourist Guide to the Yosemite Valley and the Big Tree Groves.
Under Clark's on and off stewardship through 1896, access to the park by tourists improved, and conditions in the Valley were made more hospitable to humans. Tourism started to significantly increase after a Sacramento to Stockton extension of the First Transcontinental Railroad was completed in 1869 and the Central Pacific Railroad reached Merced in 1872. The long horseback ride needed to reach the area was still a deterrent, so three stagecoach roads were built in the mid-1870s to provide better access; Coulterville Road (June 1874), Big Oak Flat Road (July 1874), and the Mariposa/Wawona Road (July 1875). A road to Glacier Point was completed in 1882 by John Conway, and the Great Sierra Wagon Road was opened in 1883 (roughly following the Mono Trail to Tuolumne Meadows).
Yosemite's oldest concession was established in 1884 when Mr. and Mrs. John Degnan established a bakery and store. Perhaps the most famous concession, the Curry Company, was started by David and Jenny Curry in 1899 (they founded Camp Curry, now known as Curry Village). The Currys lobbied reluctant park supervisors to expand concessionaire operations and development in the area. In 1900 Oliver Lippincott became the first person to drive an automobile into the Valley. Yosemite Valley Railroad, nicknamed "the short line to paradise", arrived at nearby El Portal, California in 1907. Tourists transferred from the railway to stagecoaches that traveled through Merced Canyon to reach Yosemite Valley.
Life on the Valley floor was plagued by mosquitoes and the threat of contracting diseases they carry. So in 1878 Clark used dynamite to breach a recessional moraine in the valley that impounded a swamp behind it. Numerous hiking and horse trails were also cleared, including a walking path through Mariposa Grove.
Clark and the reigning commissioners were ousted in 1880 by the California Legislature and Hutchings became the new park guardian. That same year Bunnell's account of the Valley's discovery was finally published. Hutchings in turn was removed as guardian in 1884 and was replaced by W.E. Dennison. Clark was reappointed as guardian in 1889.
[edit] John Muir's influence and the national park
Scotland-born naturalist John Muir first came to California in March 1868 and immediately set out for the Yosemite area. Muir studied the area's plants, rocks and animals in the summer of 1869 while employed by rancher Pat Delaney to accompany his sheep and sheepherder. Soon after, Hutchings hired Muir to operate a sawmill. Articles written by Muir helped to both popularize the area and increase scientific interest in it. Muir was one of the first to theorize that the major landforms in Yosemite were created by large alpine glaciers, bucking established scientists such as Josiah Whitney who regarded Muir as an amateur (see geology of the Yosemite area). Muir also wrote scientific papers on the area's biology.
Alarmed by over-grazing of meadows (especially by sheep who Muir called "hooved locusts"), logging of Giant Sequoia, and other damage, Muir changed from being a promoter and scientist to an advocate for further protection. As part of this new role he persuaded many influential people to accompany him to camp in the park, such as Ralph Waldo Emerson in 1871. On these trips Muir would try to convince his guests of the importance of putting the area under federal protection. None of his guests through the 1880s could do much for Muir's cause except for Robert Underwood Johnson, who was editor of Century Magazine. Through Johnson, Muir had a national audience for his writing and a highly motivated and crafty Congressional lobbyist.
His wish was partially answered on October 1, 1890 when the area outside the valley and sequoia grove became a national park under the un-opposed Yosemite Act. The Act withdrew these lands from "settlement, occupancy, or sale" and protected "all timber, mineral deposits, natural curiosities or wonders" along with prohibiting "wanton destruction of the fish and game and their capture or destruction for the purposes of merchandise or profit". This was the first time the federal government set aside land for such a purpose. It is important to note, that Yosemite National Park does include the entire upper drainages of two separate river watersheds (which was very important to Muir who said "you cannot save Yosemite Valley without saving its Sierran fountains."). The State of California, however, retained control of the Valley and Grove. Muir also helped persuade local officials to virtually eliminate grazing from the Yosemite High Country. A dairy herd was kept in the valley and all horses brought there grazed in its meadows, however. Muir and 181 others founded the Sierra Club in 1892, in part to lobby for the transfer of the Valley and Grove into the National Park.
[edit] Army administration and a unified national park
Like Yellowstone National Park before it, Yosemite was at first administered by the United States Army. Captain Abram Wood led the 4th Cavalry Regiment into the new park on May 19, 1891 and set up camp in Wawona, called Camp A.E. Wood (now the Wawona Campground). Each summer, 150 cavalrymen traveled from the Presidio of San Francisco to patrol the park. A major problem facing the Cavalry were the approximately 100,000 sheep that were illegally led into Yosemite's high meadows by shepherds each year. Lacking the legal authority to arrest the herders, the Cavalry instead escorted the shepherds several days hike away from their flock. This left the sheep vulnerable and thus became an excellent deterrent. By the late 1890s sheep grazing was no longer a problem, but at least one herder continued grazing his sheep in the park into the 1920s.
An extensive trail system developed by the Cavalry later formed the basis for the current trails. To mark trails, the cavalrymen blazed capital Ts into trees, a practice continued from that point onward even though none of the originally blazed trees are still standing.
Galen Clark retired as the state park's guardian in 1896, leaving the Valley and Grove under ineffective stewardship. Pre-existing problems in the state park worsened and new problems arose, but the Cavalry could only monitor the situation. Long a proponent of creating a unified Yosemite national park, Muir and his Sierra Club continued to lobby the government and influential people for the creation of a unified Yosemite National Park. In an effort to make the remote area more accessible, the Sierra Club began organizing annual trips to Yosemite, starting in 1901 (a practice that continues to the present day). The LeConte Memorial Lodge is a National Historic Landmark built in 1902 as an education center in honor of Joseph LeConte, a University of California geologist who died in Yosemite Valley the year before.
Then in May 1903, Theodore Roosevelt�– who was then President of the United States�– camped with John Muir near Glacier Point for three days. On that trip, Muir convinced Roosevelt to take control of the Valley and the Grove away from California and give it to the federal government. In 1906 Roosevelt signed a bill that did precisely that, and the Superintendent's headquarters was moved from the Wawona area to Yosemite Valley.
In 1905, however, a huge compromise had to be made to get Congressional and State of California approval; the park extent was reduced by more than 500�miles (800�km), excluding much of what is now the Ansel Adams Wilderness. This compromise excluded natural wonders such as Devils Postpile and prime wildlife habitat. Another reduction in the size of the park occurred near Wawona in 1906 and logging started soon afterward in former park-lands. In 1908 acting superintendent Major H. C. Benson said that "game is on the decrease. Each reduction of the park has cut another portion of the winter resort of game." All the boundary changes resulted in a reduction of one third of the park's area.
About 12,000�acres (4,900�ha) between Tuolumne and Merced big tree groves was added to the park in 1930 through land purchases by the federal government and matching funds provided by John D. Rockefeller. Another 8,765�acres (3,547�ha) near Wawona were added in 1932 and the Carl Inn Tract, located near the Rockefeller purchase, was secured in 1937 and 1939.
Army administration of the Park ended in 1914 as well as horse-drawn stage service. Two years of minimal civilian stewardship ensued with 15 former cavalry scouts serving as the only rangers. This task was made all the more difficult due to increasing visitation by motorists. Park visitation doubled in 1915 to 31,000 (the 1915 entrance fee for motorists was $5, more than an average worker made in a day). In an attempt to keep up with demand, stage service was briefly renewed but ended for good in 1916.
The National Park Service was formed in 1916 and Yosemite was transferred to that agency's jurisdiction with W.B. Lewis as superintendent. Tuolumne Meadows Lodge and Tioga Pass Road, along with campgrounds at Tenaya and Merced lakes, were also completed in 1916. 600 automobiles entered the east side of the Park using Tioga Road that summer. Stephen Mather, the first director of the Park Service, built the "Ranger's Club" at his own expense in 1920 to house Yosemite rangers. Mather donated it to the park and it is now maintained as a National Historic Landmark. In 1926 the "All-Weather Highway" (now State Route 140) opened, ensuring year-long visitation and supplies under normal conditions. The completion of the 0.8�mile (1.3�km) long Wawona Tunnel in 1933 was both an engineering marvel and significantly reduced the amount of travel time to the Valley from Wawona without scarring the landscape with a long road cut (the famous 'Tunnel View' is on the Valley side of the tunnel and Inspiration Point is above it). A flood, reduced lumber and mining extraction, and greatly increased automobile and bus use forced the Yosemite Valley Railway out of business in 1945. The present day Tioga Road (part of State Route 120) across the park was dedicated in 1961.
Starting in 1920, the groundwork for interpretive programs and services in national parks was laid in Yosemite by Harold C. Bryant and Loye Holmes, two professors of natural history. The position of park naturalist was created in 1921 with Ansel F. Hall performing that duty for two years. Hall pioneered the idea of having park museums act as public contact centers and general headquarters for interpretive programs�— a model followed by all later national parks in the United States and widely adapted internationally as well. Chris Jorgenson's former artist's studio was used to house the temporary museum from 1921 to 1926. Yosemite Museum, the first permanent museum in the National Park System, was completed in 1926.
[edit] The fight over Hetch Hetchy Valley
To the north of Yosemite Valley is Hetch Hetchy Valley, which was considered by many, including John Muir, to be comparable in beauty and significance to Yosemite Valley. The earliest Native peoples of Hetch Hetchy were Paiutes.
Water rights to Tuolumne River water were first sought by San Francisco in 1901 but were rejected in 1903 by Secretary of the Interior Ethan Allen Hitchcock who felt the application was "not in keeping with the public interest." Devastation of the the city by the 1906 San Francisco earthquake tipped the balance. Rights to Hetch Hetchy were granted to the City of San Francisco in 1908 by Secretary of the Interior James Garfield. Garfield wrote; "Domestic use is the highest use to which water and available storage basins.... can be put."
A long and nationally-polarized fight, pitting preservationists like Muir who wanted to leave wild areas wild against conservationists like Gifford Pinchot who wanted to manage wild areas for the betterment of mankind, ensued. Muir, aided by Robert Underwood Johnson and his Sierra Club, wrote "Dam Hetch Hetchy! As well dam for watertanks the people's cathedrals and churches, for no holier temple has ever been consecrated by the heart of man." Pinchot, who was director of the U.S. Forest Service, wrote to his close friend Roosevelt that he believed "the highest possible use which could be made of it would be to supply pure water to a great center of population." Roosevelt reluctantly sided with Pinchot.
Roosevelt's successor, Woodrow Wilson signed the Raker Act in law on December 13, 1913, which authorized construction of the O'Shaughnessy Dam. The valley was flooded in 1923 by impounding of the Tuolumne River behind the O'Shaughnessy Dam, forming the Hetch Hetchy Reservoir. The dam supplies 80% of the drinking water, and some cash from electricity sales, to San Francisco.
Shortly before Muir died he expressed the hope that "some compensating good must follow" from the Raker Act. The fight over the dam strengthened the conservation movement by popularizing it nationally.
[edit] More recent history
The Ahwahnee Hotel, built in 1927 in Yosemite Valley, is a luxury hotel decorated in Native American motifs. It was designed by the architect Gilbert Stanley Underwood who designed lodges at many of the national parks. For many years Ansel Adams produced an annual pageant there, and in World War II it was used as a rehabilitation hospital for soldiers. It is now a National Historic Landmark.
Yosemite National Park has had 11 winter floods since 1916 that have caused substantial damage to property. All of these floods took place between November 1 and January 30. The largest floods occurred in 1937, 1950, 1955, and 1997, and were in the range of 22,000 to 25,000 cubic feet (620 to 700�m³) per second, as measured at the Pohono Bridge gauging station in Yosemite Valley. After the 1950 flood, all structures in Old Yosemite Village, except for the chapel, were either moved to the Pioneer Yosemite History center in Wawona or demolished in the 1950s and 1960s. Other structures from throughout the park were also moved to the history center. Some structures in the Old Village, such as the historic 1858 Cedar Cottage, then the oldest building in Yosemite Valley, were demolished even though they weren't flooded. Back then little regard was given to historic preservation, the thought being that the "highest use" was preserving and restoring natural scenery.
Three different protected zones were added adjacent to Yosemite National Park in 1964:
These additional protected areas include areas removed from Yosemite National Park just prior to the 1906 Act as well as other public land.
A 1964 act of Congress set aside about 94% of the park in a highly protected wilderness area. No roads, motorized vehicles (except rescue helicopters and other emergency vehicles), or any development of any kind beyond trail maintenance are allowed in this area.
In 1968 the famous Yosemite Firefall, in which the embers from a bonfire were pushed off of a cliff near Glacier Point to create a spectacular effect, was ended because it drew excessively large crowds. The Firefall was occasionally performed in the 1870s and became a nightly tradition with the founding of Camp Curry.
The broader tensions in American society were felt in Yosemite in 1970, when a large number of youths gathered in the park over the summer. Rioting broke out on July 4 in Stoneman Meadow. The visitors attacked rangers with rocks and pulled mounted rangers from their horses. The National Guard was brought in to maintain order.
The late 1990s saw the high-profile murder case of Cary Stayner and some serious rock slides; one rockslide originating from the east side of Glacier Point ended near the Happy Isles of the Merced River, creating a debris field larger than several football fields. Tourism dropped a little after those incidents, but soon after returned to previous levels.
[edit] Human impact
Early park guardians took actions, such as draining swamps, that reduced the number and extent of these meadows. In the 1860s there were over 750�acres (300�ha) of meadows in the valley compared to 340�acres (140�ha) by the end of the 20th century. These modern meadows must be maintained by removing trees and shrubs.
Muir and the Sierra Club at first encouraged efforts to increase visitation. Muir wrote that even the "... frivolous and inappreciative ..." visitors were on the whole "... a most hopeful sign of the times, indicating at least the beginning of our return to nature—for going to the mountains is going home."
The first automobile entered the Valley in 1900, but growth in car traffic did not increase significantly until 1913 when they were first officially allowed to enter. In 1914, 127 cars entered the park.
Visitation rapidly swelled with the advent of the automobile. Park visitation increased from 15,154 in 1914 to 35,527 in 1918 and then 461,000 in 1929. Two thirds of a million visited in 1946. Visitation reached 1 million in 1954, 2 million by 1966, 3 million in the 1980s and 4 million in the 1990s. Car use has proportionately increased too. These millions of users have dramatically influenced the local ecosystem.
Decades of aggressive fire suppression have been replaced by a fire management program that includes the yearly use of prescribed fires. Fire is especially important to the Giant Sequoia groves, whose seeds cannot germinate without fire-touched soil.
In March 1986 the California Department of Fish and Game, the National Park Service, and the U.S. Forest Service reintroduced Bighorn Sheep just east of the park in Lee Vining Canyon. The herd reached a peak of nearly 100 individuals in 1994, but almost 60% of the herd died in the winter of 1994–1995. About 55 bighorns from the herd were counted in the 1996 census.
Brown Bears, also called grizzlies, were once the top predators in the region but went locally extinct in the 1920s. The last confirmed kill of a Yosemite grizzly occurred in Wawona in 1895. These animals figured prominently in Miwok mythology, and a sketch of a Yosemite grizzly by Charles Nahl adorns the flag of California. Inevitable losses of cattle, and danger to people, makes the prospect of reintroduction into the park remote. Other predators, such as coyote, fox, lynx, mountain lion, and wolverine were trapped for their firs by rangers to supplement their incomes. This practice continued until 1925 but predator control continued; the state lion hunter killed 43 mountain lions in Yosemite in 1927. Cooper's hawk and sharp-shinned hawk were hunted and have since became locally extinct.
The introduction of trout in Yosemite streams and lakes had a negative impact on native frog populations due to tadpole predation. Lakes and streams are no longer stocked in the park. Tule elk, which were near extinction, were housed in a pen in Yosemite before being moved to the Owens Valley in eastern California. Feeding and viewing of American black bears was encouraged by park concessionaires who provided trash for the animals to eat. Bears were a common attraction by the 1930s; In 1929 alone 81 people were treated for bear-related injuries. Troublesome bears were marked with white paint and relocated to other parts of the park. Repeat offenders were killed.
Bear feeding shows were stopped in 1940 but the Park Service continued to kill bears that habitually raided camps; 200 bears were put down between 1960 and 1972. The Park Service now emphasizes education of park visitors about proper storage of food in order to avoid having to relocate and destroy bears. Bighorn sheep, which were driven locally extinct through hunting and disease, have been reintroduced in the eastern part of the park.
The Park Service has also prohibited driving and camping in meadows, which was a common practice in the 1910s to 1930s. Cattle and horses no longer freely roam the park. Over one half billion board feet of timber were felled between World War I and 1930, when John D. Rockefeller, Jr. and the federal government bought out the Yosemite Lumber Company. Yet there were still 1300 buildings in the valley and 17�acres (6.9�ha) of the valley floor were covered by parking lots in the late 1990s.
Plans for reducing the human impact on the park were released by the Park Service in 1980. The General Management Plan specified a reduction of 17% in overnight accommodations, a 68% reduction in staff housing and removal of golf courses and tennis courts by 1990. This goal was not met but flooding in January 1997 destroyed park infrastructure in Yosemite Valley. The Yosemite Valley Plan was later established to implement the General Management Plan and over 250 other actions."Yosemite Valley Plan: The Story and the Process". National Park Service. http://www.nps.gov/archive/yose/planning/yvp/about.html. Retrieved 2010-03-27.�
Many visitors fail to realize the wild aspect of the park, and tend to treat it like a zoo�— feeding animals, petting them, taking mementos home; this is a dramatic safety issue for the visitors and is also illegal. Squirrels that feed all summer become obese, making them prey for Mountain Lions, which are a safety issue unto themselves. Food left in cars are easy pickings for the local Black Bear populations. Petting Mule Deer risks serious injury (the only person killed in Yosemite by an animal was killed by a deer). The Park Service, in conjunction with businesses and groups in the park, are trying to encourage people to experience and learn about Yosemite.
Trails and high use areas are redesigned to reduce impact. A free shuttle bus system has been developed to help relieve summer traffic congestion in the valley. Proposals to exclude cars in the summer that are not registered at a hotel or campsite within the valley have been investigated (this has already been implemented at other parks, such as Zion National Park in Utah). Many agencies in the Park offer educational activities and trips. Ironically, only about 14 square miles (36�km²) of the 1,200�mi² of the park are visited by a majority of the people.

Summary:
The known history of the Yosemite area started with Ahwahnechee and Paiute peoples who inhabited the central Sierra Nevada region of California that now includes Yosemite National Park. At the time when the first non-indigenous people entered the area, a band of Native Americans called the Ahwahnechee lived in Yosemite Valley. The California Gold Rush in the mid-19th century greatly increased the number of non-indigenous people in the area. Conflict ensued as part of the Mariposa Wars, and the Mariposa Battalion entered Yosemite Valley in 1851 while in pursuit of the Ahwaneechees led by Chief Tenaya. Accounts from this battalion were the first confirmed cases of Caucasians entering the valley.
The Yosemite Valley and the Mariposa Grove were ceded to California as a state park, in 1864, with Galen Clark as its first guardian. Access to the park by tourists improved in the early years of the park and conditions in the Valley were made more hospitable. Naturalist John Muir and others soon became alarmed about over-exploitation of the area, and helped push through the creation of Yosemite National Park in 1890. It would not be until 1906 that the Valley and Grove would be added.
Jurisdiction of the park was first under the United States Army's 4th Cavalry Regiment, and was transferred to the National Park Service in 1917. Improvements to the park helped to increase visitation during this time. Conservationists led by the Sierra Club failed to save Hetch Hetchy Valley from becoming a reservoir for San Francisco. Since then, about 94% of the park has been set aside in a highly protected wilderness area, and other protected areas were added adjacent to the park. The once-famous Yosemite Firefall, created by red hot embers being pushed off of a cliff near Glacier Point at night, has been discontinued.