(Redirected from Yosemite)
'Yosemite National Park' (pronounced "Yo-SEM-it-ee", ) is a
national park located largely in
Mariposa and
Tuolumne Counties,
California,
United States. The park covers an area of 761,266 acres or 1,189 square miles (3,081 km²) and reaches across the western slopes of the
Sierra Nevada mountain chain.
[1] Yosemite is
visited by over 3.5 million people each year, with most visitors only seeing the seven square miles (18 km²) of
Yosemite Valley.
Designated a
World Heritage Site in 1984, Yosemite is internationally recognized for its spectacular
granite cliffs,
waterfalls, clear
streams,
Giant Sequoia groves, and
biological diversity.
[ Nature & History ] About 89% of the park is designated
wilderness. It was also the first park set aside by the U.S. federal government.
[ History & Culture ] Although not the first designated
national park, Yosemite was a focal point in the development of the national park idea, largely owing to the work of people like
John Muir.
Yosemite is one of the largest and least fragmented
habitat blocks in the Sierra Nevada, and the park supports a diversity of
plants and
animals. The park has an elevation range from 2,000 to 13,114 feet (600 to 4,000 m) and contains five major
vegetation zones:
chaparral/
oak woodland, lower
montane, upper montane,
subalpine, and
alpine. Of California's 7,000 plant species, about 50% occur in the Sierra Nevada and more than 20% within Yosemite. There is suitable habitat or documentation for more than 160 rare plants in the park, with rare local geologic formations and unique
soils characterizing the restricted ranges many of these plants occupy.
The
geology of the Yosemite area is characterized by granitic rocks and remnants of older rock. About 10 million years ago, the Sierra Nevada was uplifted and then tilted to form its relatively gentle western slopes and the more dramatic eastern slopes. The uplift increased the steepness of stream and river beds, resulting in formation of deep, narrow
canyons. About 1 million years ago,
snow and
ice accumulated, forming
glaciers at the higher alpine meadows that moved down the river valleys. Ice thickness in Yosemite Valley may have reached 4,000 feet (1200 m) during the early glacial episode. The downslope movement of the ice masses cut and sculpted the U-shaped valley that attracts so many visitors to its scenic vistas today.
Geography
Yosemite National Park is located in the central Sierra Nevada of
California. It takes 3.5 hours to drive to the park from
San Francisco and about 6 hours from
Los Angeles. Yosemite is surrounded by wilderness areas: the
Ansel Adams Wilderness to the southeast, the
Hoover Wilderness to the northeast, and the
Emigrant Wilderness to the north.
The 1,189 sq mi (3,081 km²) park contains thousands of
lakes and
ponds, 1,600 miles (2,600 km) of
streams, 800 miles (1300 km) of
hiking trails, and 350 miles (560 km) of roads.
[2] Two federally designated
Wild and Scenic Rivers, the
Merced and the
Tuolumne, begin within Yosemite's borders and flow westward through the Sierra foothills, into the
Central Valley of California. Annual park visitation exceeds 3.5 million, with most visitor use concentrated in the seven square mile (18 km²) area of
Yosemite Valley.
Rocks and erosion
Almost all of the
landforms in the Yosemite area are cut from the
granitic rock of the
Sierra Nevada Batholith (a
batholith is a large mass of intrusive
igneous rock that formed deep below the surface).
[3] About 5% of the park (mostly in its eastern margin near
Mount Dana) are from
metamorphosed volcanic and
sedimentary rocks.
[4] These rocks are called ''roof pendants'' because they were once the roof of the underlying granitic rock.
[5]
Erosion acting upon different types of uplift-created joint and fracture systems is responsible for creating the valleys, canyons,
domes, and other features we see today. These joints and fracture systems do not move, and are therefore not
faults.
[6] Spacing between joints is controlled by the amount of
silica in the granite and
granodiorite rocks; more silica tends to create a more resistant rock, resulting in larger spaces between joints and fractures.
[7]
Pillars and columns, such as Washington Column and Lost Arrow, are created by cross joints.
Erosion acting on master joints is responsible for creating valleys and later canyons.
The single most erosive force over the last few million years has been large alpine
glaciers, which have turned the previously V-shaped river-cut valleys into U-shaped glacial-cut canyons (such as
Yosemite Valley and
Hetch Hetchy Valley).
Exfoliation (caused by the tendency of
crystals in
plutonic rocks to expand at the surface) acting on granitic rock with widely spaced joints is responsible for creating domes such as
Half Dome and
North Dome and inset arches like Royal Arches.
Popular features
Yosemite Valley represents only one percent of the park area, but this is where most visitors arrive and stay.
El Capitan, a prominent granite cliff that looms over the valley, is one of the most popular
rock climbing destinations in the world because of its diverse range of climbing routes in addition to its year-round accessibility.
Granite domes such as
Sentinel Rock and
Half Dome rise 3,000 feet and 4,800 feet (900 and 1,450 m), respectively, above the valley floor.
The high country of Yosemite contains beautiful areas such as
Tuolumne Meadows,
Dana Meadows, the
Clark Range, the
Cathedral Range, and the
Kuna Crest. The Sierra crest and the
Pacific Crest Trail run through Yosemite, with peaks of red
metamorphic rock, such as
Mount Dana and
Mount Gibbs, and
granite peaks, such as
Mount Conness.
Mount Lyell is the highest point in the park.
The park has three groves of ancient
Giant Sequoia (''Sequoiadendron giganteum'')
trees; the
Mariposa Grove (200 trees), the
Tuolumne Grove (25 trees), and the
Merced Grove (20 trees).
Giant Sequoia are the most massive trees in the world and are one of the tallest and longest-lived (
Coast Redwoods that live along the
Northern Californian coast are the tallest and the
Great Basin Bristlecone Pine of
Eastern California are the oldest). These trees were much more widespread before the start of the last Ice Age.
[8]
Water and ice
Tuolumne and
Merced River systems originate along the crest of the Sierra Nevada in the park and have carved river canyons 3,000 to 4,000 feet (900 to 1,200 m) deep. The Tuolumne River drains the entire northern portion of the park, an area of approximately 680 square miles (1,760 km²). The Merced River begins in the park's southern peaks, primarily the
Cathedral and
Clark Ranges, and drains an area of approximately 511 square miles (1,320 km²).
[ Water Overview ]
Hydrologic processes, including
glaciation,
flooding, and fluvial geomorphic response, have been fundamental in creating landforms in the park.
The park also contains approximately 3,200
lakes (greater than 100 m²), two
reservoirs, and 1,700 miles (2,700 km) of streams, all of which help form these two large
watersheds.
[ Hydrology and Watersheds ] Wetlands in Yosemite occur in valley bottoms throughout the park, and are often hydrologically linked to nearby lakes and rivers through seasonal flooding and groundwater movement.
Meadow habitats, distributed at elevations from 3,000 to 11,000 feet (900 to 3,500 m) in the park, are generally wetlands, as are the
riparian habitats found on the banks of Yosemite's numerous streams and rivers.
[ Wetland Vegetation ]
Bridalveil Fall flows from a U-shaped hanging valley that was created by a tributary glacier.
Yosemite is famous for its
high concentration of waterfalls in a small area. Numerous sheer drops, glacial steps and
hanging valleys in the park provide many places for
waterfalls to exist, especially during April, May, and June (the snowmelt season). Located in Yosemite Valley, the 2,425-foot-high (782 m)
Yosemite Falls is the highest in
North America. Also in the valley is the much lower volume
Ribbon Falls, which has the highest single vertical drop, 1,612 feet (492 m).
Perhaps the most prominent of the Yosemite waterfalls is
Bridalveil Fall, which is the waterfall seen from the Tunnel View viewpoint at the east end of the
Wawona Tunnel. Wapama Falls in
Hetch Hetchy Valley is another notable waterfall. Hundreds of
ephemeral waterfalls also exist in the park.
All
glaciers in the park are relatively small glaciers that occupy areas that are in almost permanent shade, such as north- and northeast-facing
cirques.
Lyell Glacier is the largest glacier in the Sierra Nevada (and therefore the park) and covers 160 acres (65 ha).
[9] None of the Yosemite glaciers are a remnant of the much, much larger
Ice Age alpine glaciers responsible for sculpting the Yosemite landscape. Instead, they were formed during one of the
neoglacial episodes that have occurred since the thawing of the Ice Age (such as the
Little Ice Age).
[10] Global warming has reduced the number and size of glaciers around the world. Many Yosemite glaciers, including Merced Glacier, which was discovered by
John Muir in 1871 and bolstered his glacial origins theory of the Yosemite area, have disappeared and most of the others have lost up to 75% of their surface area.
Climate
Yosemite has a
Mediterranean climate, meaning most precipitation falls during the mild winter, and the other seasons are nearly dry (less than 3% of precipitation falls during the long, hot summers).
[11] Due to
orographic lift, precipitation increases with elevation up to 8,000 feet (2,400 m) where it slowly decreases to the crest. Precipitation amounts vary from 36 inches (915 mm) at 4,000 feet (1,200 m) elevation to 50 inches (1,200 mm) at 8,600 feet (2,600 m). Snow does not typically persist on the ground until November in the high country. It accumulates all winter and into March or early April.
[12]
Temperature decreases with increasing elevation. Temperature extremes are moderated by the fact that Yosemite is only about 100 miles (160 km) from the
Pacific Ocean. An anticyclone sits off the coast of California in the summer, sending cool air masses toward the Sierra Nevada that result in clean dry air in the Yosemite area.
Mean daily temperatures range from 25 to 53
°F (-3.9 to 11.5
°C) at Tuolumne Meadows at 8,600 feet (2,600 m). At the Wawona Entrance (elevation 5,130 feet; 1,564 m), mean daily temperature ranges from 36 to 67 °F (2.2 to 19.4 °C). At the lower elevations below 5,000 feet (1525 m), temperatures are hotter; the mean daily high temperature at Yosemite Valley (elevation 3,966 feet; 1,209 m) varies from 46 to 90 °F (7.8 to 32.2 °C). At elevations above 8,000 feet (2,440 m), the hot, dry summer temperatures are moderated by frequent summer
thunderstorms, along with snow that can persist into July. The combination of dry
vegetation, low relative
humidity, and thunderstorms results in frequent
lightning-caused
fires as well.
History
Main articles: History of the Yosemite area
Ahwahneechee and the Mariposa Wars
Paiute ceremony in 1872 at current site of Yosemite Lodge
and
Sierra Miwok peoples lived in the area for decades before the first white explorations into the region. A band of
Native Americans called the Ahwahneechee lived in
Yosemite Valley when the first non-
indigenous people entered it.
[13]
The
California Gold Rush in the mid-19th century dramatically increased white travel in the area.
United States Army Major
Jim Savage led the
Mariposa Battalion into the west end of Yosemite Valley in 1851 while in pursuit of around 200 Ahwaneechees led by
Chief Tenaya as part of the
Mariposa Wars.
[14] Accounts from this battalion were the first confirmed cases of Caucasians entering the valley. 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''. Bunnell is credited with naming the valley from his interviews with Chief Tenaya. Bunnell wrote that Chief Tenaya was the founder of the Pai-Ute Colony of Ah-wah-nee.
13 The Miwoks (and most white settlers) considered the Ahwahneechee to be especially violent due to their frequent territorial disputes, and the Miwok word "yohhe'meti" literally means "they are killers".
[15] Correspondence and articles written by members of the battalion helped to popularize the valley and surrounding area.
Tenaya and the rest of the Ahwahneechee were eventually captured and their village burned; they were removed to a
reservation near
Fresno, California. Some were later allowed to return to the valley, but got in trouble after attacking a group of eight gold
miners in the spring of 1852.
[16] The band fled and took refuge with the nearby
Mono tribe; but after stealing some horses from their hosts, the Ahwahneechees were tracked down and killed by the Monos. A reconstructed "Indian Village of Ahwahnee" is now located behind the Yosemite Museum, which is next to the Yosemite Valley Visitor Center.
Early tourists
Entrepreneur
James Mason Hutchings, artist
Thomas Ayres and two others ventured into the area in 1855, becoming the valley's first tourists.
Hutchings wrote articles and books about this and later excursions in the area, and Ayres' sketches became the first accurate drawings of many prominent features. Photographer
Charles Leander Weed took the first
photographs of the Valley's features in 1859.
Later photographers included
Ansel Adams.
Wawona was an Indian encampment in what is now the southwestern part of the park. Settler
Galen Clark discovered the
Mariposa Grove of
Giant Sequoia in Wawona in 1857. Simple lodgings were built, as were roads to the area. In 1879, the
Wawona Hotel was built to serve tourists visiting the Grove. As tourism increased, so did the number of trails and hotels.
Yosemite Grant
Concerned by the effects of commercial interests, prominent citizens including
Galen Clark and Senator
John Conness advocated for protection of the area. A park bill passed both houses of the
U.S. Congress, and was signed by
President Abraham Lincoln on
June 30 1864, creating the Yosemite Grant.
[17] Yosemite Valley and the Mariposa Grove were ceded to
California as a
state park, and a board of commissioners was proclaimed two years later. The Yosemite Grant was a landmark bill, predating the establishment of
Yellowstone National Park, the first official "National Park".
Galen Clark was appointed by the commission as the Grant's first guardian, but neither Clark nor the commissioners had the authority to evict
homesteaders (which included Hutchings).
The issue was not settled until 1875 when the homesteader land holdings were invalidated. Clark and the reigning commissioners were ousted in 1880, and Hutchings became the new park guardian.
Access to the park by tourists improved in the early years of the park, and conditions in the Valley were made more hospitable. Tourism significantly increased after the
First Transcontinental Railroad was completed in 1869, but the long horseback ride to reach the area was a deterrent.
Three
stagecoach roads were built in the mid-1870s to provide better access for the growing number of visitors to the Valley.
Scottish-born naturalist
John Muir wrote articles popularizing the area and increasing 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.
[18] Muir wrote scientific papers on the area's biology.
Increased protection efforts
Overgrazing of
meadows (especially by
sheep),
logging of Giant Sequoia, and other damage caused Muir to become an advocate for further protection. Muir convinced prominent guests of the importance of putting the area under federal protection; one such guest was
Robert Underwood Johnson, editor of ''
Century Magazine''. Muir and Johnson lobbied Congress for the Act that created Yosemite National Park on
October 1 1890.
[19] 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.
Fallen Monarch and F Troop of U.S. Cavalry
The newly created national park came under the jurisdiction of the
United States Army's
Fourth Cavalry Regiment on
May 19 1891, which set up camp in Wawona.
By the late 1890s, sheep grazing was no longer a problem, and the Army made many other improvements. The Cavalry could not intervene to help the worsening condition of the Valley or Grove.
Muir and his
Sierra Club continued to lobby the government and influential people for the creation of a unified Yosemite National Park. In May 1903, President
Theodore Roosevelt camped with 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 return it to the federal government. In 1906, Roosevelt signed a bill that did precisely that.
Later history
An
American Black Bear with a conspicuous ear tag browsing on its natural foods in Yosemite Valley
The
National Park Service was formed in 1916, and Yosemite was transferred to that agency's jurisdiction.
Tuolumne Meadows Lodge,
Tioga Pass Road, and campgrounds at Tenaya and Merced lakes were completed in 1916.
[20] Automobiles started to enter the park in ever-increasing numbers following the construction of all-weather highways to the park. The Yosemite Museum was founded in 1926 through the efforts of
Ansel Franklin Hall.
[21]
In 1903, a dam in the northern portion of the park was proposed. Located in the
Hetch Hetchy Valley, its purpose was to provide water and
hydroelectric power to
San Francisco. Preservationists like Muir and his
Sierra Club opposed the project, while
conservationists like
Gifford Pinchot supported it. In 1913, the U.S. Congress authorized the
O'Shaughnessy Dam through passage of the
Raker Act.
[22]
More recently, preservationists persuaded Congress to designate 677,600 acres (2,742 km²), or about 89% of the park, as the 'Yosemite Wilderness' — a highly protected
wilderness area.
[23] The Park Service has reduced artificial inducements to visit the park, such as the ''
Firefall'', in which red-hot embers were pushed off a cliff near
Glacier Point at night.
Traffic congestion in Yosemite Valley during the summer months has become a concern. Plans to exclude all automobiles in the summer that are not registered at a hotel or campground within the valley have been investigated; this would put summer day-use visitors in the valley on a free shuttle bus system, on bicycles, or on foot.
Yosemite Park & Curry Company
In the early years of the park, different companies ran multiple hotels and resorts. These resorts included the
Wawona Hotel, the
Yosemite Park Lodge, and
Camp Curry, a tent cabin site in Yosemite Valley. The ''Yosemite Park & Curry Company'' was formed in 1925 to consolidate those often-competing concessions. The Park Service granted the newly formed company exclusive right to operate hotels, restaurants and most stores in Yosemite. Two years later, the new company was headquartered on the mezzanine level of its new hotel,
The Ahwahnee. The Yosemite Park and Curry Company ran the concessions in the park for over 50 years until the company was sold in the late 1970s to United States Natural Resources (USNR) and a couple of years later to MCA which operated Universal Studios. During those ownership changes, the Curry Company name continued. In 1993, MCA was acquired by Matsushita. Then Secretary of the Interior Manuel Lujan objected to a Japanese firm operating concessions in a U.S. national park, so to avoid delay of federal approval of the acquisition, Matsushita arranged for the sale of the concessions company, ownership of its concession properties was transferred to the federal government, and the Yosemite Park and Curry Co. name was retired. The park concession contract is now operated by
Delaware North Companies "Parks and Resorts" (the official concessionaire name in DNC Parks and Resorts @ Yosemite).
Geology
Main articles: Geology of the Yosemite area
Tectonic and volcanic activity
The area of the park was astride a passive
continental margin during the
Precambrian and early
Paleozoic.
Sediment was derived from continental sources and was deposited in shallow water. These rocks have since been
metamorphosed.
Generalized geologic map of the Yosemite area (USGS image)
Heat generated from the
Farallon Plate subducting below the
North American Plate led to the creation of an
island arc of volcanoes on the west coast of proto-
North America between the late
Devonian and
Permian periods.
[24] Later volcanism in the
Jurassic intruded and covered these rocks in what may have been magmatic activity associated with the early stages of the creation of the
Sierra Nevada Batholith. 95% of these rocks were eventually removed by uplifted-accelerated erosion.
The first phase of regional
plutonism started 210 million years ago in the late Triassic and continued throughout the Jurassic to about 150 million years before present (
BP).
Around the same time, the
Nevadan orogeny built the Nevadan mountain range (also called the Ancestral Sierra Nevada) to a height of 15,000 feet (4500 m). This was directly part of the creation of the Sierra Nevada Batholith, and the resulting rocks were mostly
granitic in composition and emplaced about 6 miles (10 km) below the surface.
[25] The second major pluton emplacement phase lasted from about 120 million to 80 million years ago during the
Cretaceous.
This was part of the
Sevier orogeny.
Starting 20 million years ago (in the
Cenozoic) and lasting until 5 million years ago, a now-extinct extension of
Cascade Range volcanoes erupted, bringing large amounts of igneous material in the area. These igneous deposits blanketed the region north of the Yosemite region. Volcanic activity persisted past 5 million years
BP east of the current park borders in the
Mono Lake and
Long Valley areas.
Uplift and erosion
Starting 10 million years ago, vertical movement along the Sierra fault started to uplift the Sierra Nevada. Subsequent tilting of the Sierra block and the resulting accelerated uplift of the Sierra Nevada increased the
gradient of western-flowing streams.
[26] The streams consequently ran faster and thus cut their valleys more quickly. Additional uplift occurred when major faults developed to the east, especially the creation of
Owens Valley from
Basin and Range-associated extensional forces. Uplift of the Sierra accelerated again about two million years ago during the
Pleistocene.
The uplifting and increased erosion exposed granitic rocks in the area to surface pressures, resulting in
exfoliation (responsible for the rounded shape of the many domes in the park) and mass wasting following the numerous fracture joint planes (cracks; especially vertical ones) in the now solidified plutons.
[27] Pleistocene glaciers further accelerated this process and the larger ones transported the resulting
talus and
till from valley floors.
Numerous vertical joint planes controlled where and how fast erosion took place. Most of these long, linear and very deep cracks trend northeast or northwest and form parallel, often regularly spaced sets. They were created by uplift-associated pressure release and by the unloading of overlying rock via erosion.
Sculpting by glaciers
View from Glacier Point
A series of
glaciations further modified the region starting about 2 to 3 million years ago and ending sometime around 10,000
BP. At least four major glaciations have occurred in the Sierra Nevada, locally called the Sherwin (also called the pre-Tahoe), Tahoe, Tenaya, and Tioga.
The Sherwin glaciers were the largest, filling Yosemite and other valleys, while later stages produced much smaller glaciers. A Sherwin-age glacier was almost surely responsible for the major excavation and shaping of Yosemite Valley and other canyons in the area.
Glacial systems reached depths of up to 4000 feet (1200 m) and left their marks in the Yosemite area. The longest glacier in the Yosemite area ran down the Grand Canyon of the
Tuolumne River for 60 miles (95 km), passing well beyond
Hetch Hetchy Valley. Merced Glacier flowed out of Yosemite Valley and into the
Merced River Gorge. Lee Vining Glacier carved Lee Vining Canyon and emptied into Lake Russel (the much-enlarged ice age version of
Mono Lake). Only the highest peaks, such as
Mount Dana and
Mount Conness, were not covered by glaciers. Retreating glaciers often left recessional
moraines that impounded lakes such as the 5.5 mile (8.9 km) long Lake Yosemite (a shallow lake that periodically covered much of the floor of Yosemite Valley).
[28]
Biology
Habitats
With habitats ranging from thick foothill
chaparral to expanses of alpine rock, Yosemite National Park supports over 250 species of
vertebrates, which include
fish,
amphibians,
reptiles,
birds, and
mammals. This high diversity of species is also the result of
habitats in Yosemite that are largely intact, compared to areas outside the park where various human activities have resulted in habitat degradation or destruction.
[ Wildlife Overview ]
Along much of Yosemite's western boundary, habitats are dominated by mixed
coniferous forests of
Ponderosa Pine,
Sugar Pine,
Incense-cedar,
White Fir, and
Douglas Fir, and a few stands of
Giant Sequoia, interspersed by areas of
Black Oak and
Canyon Live Oak. A relatively high diversity of wildlife species are supported by these habitats, due to relatively mild, lower-elevation
climate and the mixture of habitat types and plant species. Wildlife species typically found in these habitats include
Black Bear,
Bobcat,
Gray Fox,
Mule deer,
Mountain Kingsnake,
Gilbert's Skink,
White-headed Woodpecker,
Brown Creeper,
Spotted Owl, and a wide variety of
bat species. In the case of bats, large snags are important as roost sites.
Going higher in elevation, the coniferous forests become purer stands of
Red Fir,
Western White Pine,
Jeffrey Pine,
Lodgepole Pine, and the occasional
Foxtail pine. Fewer wildlife species tend to be found in these habitats, due to their higher elevation and lower complexity. Species likely to be found include
Golden-mantled Ground Squirrel,
Chickaree,
Marten,
Steller's Jay,
Hermit Thrush, and
Northern Goshawk. Reptiles are not common, but include
Rubber Boa,
western fence lizard, and
Northern Alligator Lizard.
As the landscape rises, trees become smaller and more sparse, with stands broken by areas of exposed
granite. These include Lodgepole Pine,
Whitebark Pine, and
Mountain Hemlock that, at highest elevations, give way to vast expanses of granite as treeline is reached. The climate in these habitats is harsh and the growing season is short, but species such as
Pika,
Yellow-bellied Marmot,
White-tailed Jackrabbit,
Clark's Nutcracker, and
Rosy Finch are adapted to these conditions. Also, the treeless alpine habitats are the areas favored by
Sierra Nevada Bighorn Sheep. This species, however, is now found in the Yosemite area only around Tioga Pass, where a small, reintroduced population exists.
At a variety of elevations, meadows provide important, productive habitat for wildlife. Animals come to feed on the green
grasses and use the flowing and standing water found in many meadows.
Predators, in turn, are attracted to these areas. The interface between meadow and forest is also favored by many animal species because of the proximity of open areas for foraging and cover for protection. Species that are highly dependent upon
meadow habitat include
Great Gray Owl,
Willow Flycatcher,
Yosemite Toad, and
Mountain Beaver.
Management issues
Despite the richness of high-quality habitats in Yosemite, three species have become
extinct in the park within historical time, and another 37 species currently have special status under either California or federal
endangered species legislation. The most serious current threats to Yosemite's wildlife and the ecosystems they occupy include loss of a natural fire regime,
exotic species,
air pollution,
habitat fragmentation, and
climate change. On a more local basis, factors such as
road kills and the availability of human food have affected some wildlife species.
The black bears of Yosemite were once famous for breaking into parked cars to steal food. They were also an encouraged tourist sight for many years at the park's
garbage dumps, where bears congregated to eat park visitors' garbage and tourists gathered to photograph the bears. Increasing encounters between bears and humans and increasing damage to property led to an aggressive campaign to discourage bears from relying on human food or interacting with people and their property. The open-air dumps were closed; all trash receptacles were replaced with
bear-proof receptacles; all campgrounds were equipped with bear-proof food lockers so that people would not leave food in their vehicles, which were easy targets for the powerful and resourceful bears. Because bears who show aggression towards people usually are eventually destroyed, park personnel have continued to come up with innovative ways to have bears associate humans and their property with unpleasant experiences, such as being hit with
rubber bullets. Today, about 30 bears a year are captured and
ear-tagged and their
DNA is sampled so that, when bear damage occurs, rangers can ascertain which bear is causing the problem.
[29]
Increasing
ozone pollution is causing tissue damage to the massive
Giant Sequoia trees in the park. This makes them more vulnerable to
insect infestation and
disease. Since the
cones of these trees require fire-touched soil to
germinate, historic
fire suppression has reduced these trees' ability to reproduce. The current policy of setting
prescribed fires will hopefully help the germination issue.
Yosemite National Park has documented more than 130 non-native plant
species within park boundaries. These non-native plants were introduced into Yosemite following the migration of early
Euro-American settlers in the late 1850s. Natural and human-caused disturbances, such as wildland fires and construction activities, have contributed to a rapid increase in the spread of non-native plants. A number of these species aggressively invade and displace the native plant communities, resulting in impacts on the park's resources. Non-native plants can bring about significant changes in park ecosystems by altering the native plant communities and the processes that support them. Some non-native species may cause an increase in the fire frequency of an area or increase the available
nitrogen in the soil that may allow more non-native plants to become established. Many non-native species, such as
Yellow Star Thistle (''Centaurea solstitialis''), are able to produce a long
tap root that allows them to out-compete the native plants for available water.
[ Exotic Plants ]
Bull Thistle (''Cirsium vulgare''),
Common Mullein (''Verbascum thapsus''), and
Klamath Weed (''Hypericum perforatum'') have been identified as noxious
pests in Yosemite since the 1940s. Additional species that have been recognized more recently as aggressive and requiring control are Yellow Star Thistle,
Sweet Clovers (''Melilotus'' spp.),
Himalayan Blackberry (''
Rubus discolor''),
Cut-leaved Blackberry (''Rubus laciniatus'') and
Periwinkle (''Vinca major'').
Activities
The Yosemite Hybrid Shuttle, Yosemite's free shuttle bus system
Yosemite Valley is open year-round, but much of the remaining park is closed due to snow in late fall and does not re-open until mid to late spring. Open-air tours around Yosemite Valley and the
Mariposa Grove of
Giant Sequoias are available. Many people enjoy short walks and longer hikes to waterfalls in Yosemite Valley, or walks amongst Giant Sequoias in the Mariposa, Tuolumne, or Merced Groves. Others like to drive or take a tour bus to
Glacier Point (summer-fall) to see a spectacular view of Yosemite Valley and the high country, or drive along the scenic
Tioga Road to
Tuolumne Meadows (summer-fall) and go for a walk or hike.
Most people who enter the park stay just for the day, and only visit locations within Yosemite Valley that are easily accessible via their automobile (there is a
US$20 per automobile user fee to enter the park).
Traffic congestion in the valley is therefore a serious problem during the peak visiting season, summer. A free
shuttle bus system operates year-round in the valley, and
park rangers encourage people to use this system since parking within the valley during the summer is often nearly impossible to find.
[30] Almost all of the park, however, is highly-protected roadless
wilderness that does not allow any
motorized vehicles and requires permits for overnight stays.
In addition to exploring the natural features of the park, visitors can also learn about the
natural and
cultural history of Yosemite at a number of facilities in the valley: the Yosemite Valley Visitor Center, the adjoining Yosemite Museum, and the Nature Center at Happy Isles. There are also two
National Historic Landmarks: the LeConte Memorial Lodge (Yosemite's first public visitor center), and the world-famous
Ahwahnee Hotel.
Hiking
Over 800 miles (1300 km) of trails are available to hikers
—anything from the easy stroll, to the grueling hikes up several park mountains, to multiple-day
backpack trips.
The park can be divided into 5 sections for the day-user—Yosemite Valley, Wawona/Mariposa Grove/ Glacier Point, Tuolumne Meadows, Hetch Hetchy, and
Crane Flat/
White Wolf. Numerous books describe park trails, and free information is available from the Park Service in Yosemite. Most park workers strongly encourage guests to experience portions of the park other than Yosemite Valley.
Between late spring and early fall, much of the park is open to multiple-day backpack trips. All overnight trips into the back country require a wilderness permit
and most require approved
bear-resistant food storage.
[ Food storage ]
Biking
Bicycle rentals are available in Yosemite Valley spring through fall. Over 12 miles of paved bike paths are available in Yosemite Valley. In addition, bicyclists can ride on regular roads.
Helmets are required by law for children under 18 years of age. Off-trail riding and
mountain biking are not permitted in Yosemite National Park.
[31]
Driving destinations
While some locations in Yosemite require hiking, other locations can be observed via automobile transportation. Driving locations also allow guests to observe the night sky in locations other than their campsite or lodge. All of the roads in Yosemite are scenic, but the most famous is the
Tioga Road, typically open from late May or early June through November.
[ Auto Touring ]
As an alternative to driving, bicycles are allowed on the roads. However, bicycles are only allowed off-road on 12 miles of paved trails in Yosemite Valley itself; mountain biking is not allowed.
[32]
Climbing
Rock climbing is an important part of Yosemite.
[33] Camp 4—a walk-in campground in Yosemite Valley—was instrumental in the development of rock climbing as a sport, and is listed on the
National Register of Historic Places.
[ ] Climbers can generally be spotted in the snow-free months on anything from ten-foot-high (3 m) boulders to the 3,300 foot (1 km) face of
El Capitan. Classes are offered by numerous groups on rock climbing.
Winter activities
A ranger-guided
snowshoe walk in the park
Many of the roads in the park close due to heavy snow in winter; however, Yosemite Valley is open all year long.
Downhill skiing is available at the
Badger Pass Ski Area—the oldest downhill skiing area in California, offering downhill skiing from mid-December through early April.
[34] Much of the park is open to
cross-country skiing and
snowshoeing, with several backcountry ski huts open for use.
[ Tuolumne Meadows Winter Conditions Update ][ Winter Wilderness Travel ] Wilderness permits are required for backcountry overnight ski trips.
[ Permits ]
The
Bracebridge dinner is an annual holiday event, held since 1927 at the
Ahwahnee Hotel, inspired by
Washington Irving's descriptions of Squire Bracebridge and
English Christmas traditions of the 1700s in his ''Sketch Book''. Between 1929 and 1973, the show was organized by
Ansel Adams.
[35]
See also
★
Geology of the Yosemite area
★
History of the Yosemite area
★
List of guidebooks about the Sierra Nevada
Notes
1. Harris, ''Geology of National Parks'' (5th ed), p. 324.
2. Nature & Science
3. Harris, ''Geology of National Parks'' (5th ed), page 329
4. Geology: The Making of the Landscape
5. Geological Survey Professional Paper 160: Geologic History of the Yosemite Valley - The Sierra Block
6. Harris, ''Geology of National Parks'' (5th ed.), p. 331.
7. Kiver, ''Geology of U.S. Parklands'' (5th ed.), p. 220.
8. Kiver, ''Geology of U.S. Parklands'' (5th ed), page 227
9. Kiver, ''Geology of U.S. Parklands'' (5th ed.), p. 228.
10. Harris, ''Geology of National Parks'' (5th ed.), p. 340.
11. Wuerthner, ''Yosemite: A Visitor's Companion'' (1st ed.), p. 8.
12. Climate
13. Discovery of the Yosemite and the Indian War of 1851 Which Led to That Event ISBN 0-93966-658-8.
14. Harris, ''Geology of the National Parks'' (5th ed.), p. 326.
15. Origin of the Word Yosemite
16. Schaffer, ''Yosemite National Park'' (4th ed.), p. 46.
17. Schaffer, ''Yosemite National Park'' (4th ed.), p. 48.
18. Schaffer, ''Yosemite National Park'' (4th ed.), p. 49.
19. Schaffer, ''Yosemite National Park'' (4th ed.), p. 50.
20. Shaffer, ''Yosemite National Park'' (4th ed.), p. 52.
21. National Park Service, ''Yosemite: Official National Park Handbook'', p. 117.
22. Schaffer, ''Yosemite National Park'' (4th ed.), p. 51.
23. PUBLIC LAW. 98-425 98th U.S. Congress
24. Harris, ''Geology of National Parks'' (5th ed.), p. 328.
25. Harris, ''Geology of National Parks'' (5th ed.), p. 337.
26. Harris, ''Geology of National Parks'' (5th ed.), p. 339.
27. Harris, ''Geology of National Parks'' (5th ed.), p. 332.
28. Harris, ''Geology of National Parks'' (5th ed.), p. 333.
29. DNA to Help Identify "Problem" Bears at Yosemite
30. Yosemite Valley Shuttle Bus
31. Plan Your Visit
32. Biking
33. Climbing
34. Skiing
35. Ansel Adams' love of Yosemite lives
References
★ Harris, Ann G. ''Geology of National Parks: Fifth Edition''. (Iowa, Kendall/Hunt Publishing; 1998) ISBN 0-7872-5353-7.
★ Kiver, Eugene P. and David V. Harris. ''Geology of U.S. Parklands: Fifth Edition''. (Jonh Wiley & Sons; New York; 1999) ISBN 0-471-33218-6.
★
National Park Service: Yosemite National Park (adapted public domain text)
★
★
Climate (22-Dec-2004) Retrieved on
January 27 2007
★
★
Exotic Vegetation (22-Dec-2004) Retrieved on
January 27 2007
★
★
Nature & History (13-Oct-2006) Retrieved on
January 27 2007
★
★
Water Resources Overview (22-Dec-2004) Retrieved on
January 27 2007
★
★
Wildlife Overview (22-Dec-2004) Retrieved on
January 27 2007
★ Schaffer, Jeffrey P. ''Yosemite National Park: A Natural History Guide to Yosemite and Its Trails''. (Wilderness Press, Berkeley; 1999) ISBN 0-89997-244-6.
★ Wuerthner, George. ''Yosemite: A Visitor's Companion''. (Stackpole Books; 1994) ISBN 0-8117-2598-7.
★ ''Yosemite: Official National Park Service Handbook (no. 138)'', Division of Publications, National Park Service.
External links
★
National Park Service: Yosemite National Park
★
★
The Yosemite Association
★
Historic Yosemite Indian Chiefs - with photos
★
Historic Photographs of Yosemite National Park taken by Edith Irvine
★
Scenic photos of Yosemite
★
Daily updating time-lapse movies of Yosemite
★
Gigapixel photos of Yosemite
★
Yosemite Hiking Information
★
Interactive hiking map of the Yosemite National Park
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