Yosemite Valley ( ; Yosemite, Miwok for "killer") is a glacial valley in Yosemite National Park in the western Sierra Nevada mountains of Central California, United States. The valley is about long and deep, surrounded by high granite summits such as Half Dome and El Capitan, and densely forested with pines. The valley is drained by the Merced River, and a multitude of streams and waterfalls flow into it, including Tenaya, Illilouette, Yosemite and Bridalveil Creeks. Yosemite Falls is the highest waterfall in North America and is a big attraction, especially in the spring, when the water flow is at its peak. The valley is renowned for its natural environment and is regarded as the centerpiece of Yosemite National Park.
The valley is the main attraction in the park for the majority of visitors and a bustling hub of activity during tourist season in the summer months. Most visitors enter the valley from roads to the west and pass through the Tunnel View entrance. Visitor facilities are in the center of the valley. There are both hiking trail loops that stay within the valley and trailheads that lead to higher elevations.
Descriptions
Yosemite Valley is on the western slope of the Sierra Nevada mountains, east of San Francisco. It stretches for in a roughly east–west direction, with an average width of about .
Yosemite Valley represents only one percent of the park area, but it is where most visitors arrive and stay. More than half a dozen creeks tumble from hanging valleys at the top of granite cliffs that can rise above the valley floor, which itself is above sea level. These streams combine into the Merced River, which flows out from the western end of the valley, down the rest of its canyon to the San Joaquin Valley. The flat floor of Yosemite Valley holds both forest and large open meadows, which have views of the surrounding crests and waterfalls.
Below is a description of these features, looking first at the walls above, moving west to east as a visitor does when entering the valley, then visiting the waterfalls and other water features, returning east to west with the flow of water.
The first view of Yosemite Valley many visitors see is the Tunnel View. So many paintings were made from a viewpoint nearby that the National Park Service named that viewpoint Artist Point. The view from the lower (western) end of the Valley contains the great granite monolith El Capitan on the left, and Cathedral Rocks on the right with Bridalveil Fall. Just past this spot the Valley suddenly widens with the Cathedral Spires, then the pointed obelisk of Sentinel Rock to the south. Across the Valley on the northern side are the Three Brothers, rising one above the other like gables built on the same angle – the highest crest is Eagle Peak, with the two below known as the Middle and Lower Brothers.
To this point the Valley has been curving gently to the left (north). Now a grand curve back to the right begins, with Yosemite Falls on the north, followed by the Royal Arches, topped by North Dome. Opposite, to the south, is Glacier Point, above the Valley floor. At this point the Valley splits in two, one section slanting northeast, with the other curving from south to southeast. Between them, at the eastern end of the valley, is Half Dome, among the most prominent natural features in the Sierra Nevada. Above and to the northeast of Half Dome is Clouds Rest, at ; it is the highest point near Yosemite Valley.
Water Snow melting in the Sierra forms creeks and lakes. In the surrounding region, these creeks flow to the edge of the Valley to form cataracts and waterfalls.
A fan of creeks and forks of the Merced River take drainage from the Sierra crest and combine at Merced Lake. The Merced then flows down to the end of its canyon (Little Yosemite Valley), where it begins what is often called the Giant Staircase. The first drop is Nevada Fall, which drops , bouncing off the granite slope below it. Below is Vernal Fall, high, one of the most picturesque waterfalls in the Valley. The Merced then descends rapids to meet Illilouette Creek, which drops from the valley rim to form Illilouette Fall. They combine at the base of the gorges that contain each stream, and then flow around the Happy Isles to meet Tenaya Creek at the eastern end of Yosemite Valley proper.
Tenaya Creek flows southwest from Tenaya Lake and down Tenaya Canyon, finally flowing between Half Dome and North Dome before joining the Merced River. The following falls tumble from the Valley rim to join it at various points:
Yosemite Falls Upper Yosemite Fall , the middle cascades , and Lower Yosemite Fall . (Yosemite Creek) Snow Creek Falls Sentinel Falls Ribbon Fall Royal Arch Cascade Lehamite Falls Staircase Falls Bridalveil Fall . (Bridalveil Creek) Nevada Fall Silver Strand Falls Vernal Fall
Natural Yosemite Valley
Geology
The features in Yosemite Valley are made of granitic rock emplaced as plutons miles deep during the late Cretaceous. Over time the Sierra Nevada was uplifted, exposing this rock to erosion at the surface.
There are many types of granite found in Yosemite Valley with the most prominent being El Capitan Granite, Sentinel Granodiorite, Taft Granite, and Half Dome Granodiorite. Majority of the minerals found in the granite include quartz, potassium and plagioclase feldspar, biotite, and hornsblende. The oldest of these granitic rocks, at 114 million years, occur along the Merced River Gorge west of the valley. The El Capitan pluton intruded the valley, forming most of the granitic rock that makes up much of the central part of the valley, including Cathedral Rocks, Three Brothers, and El Capitan. The youngest Yosemite Valley pluton is the 87-million-year-old Half Dome granodiorite, which makes up most of the rock at Glacier Point, the Royal Arches, and its namesake, Half Dome.
Before Yosemite Valley was a valley, it was formed by sediment deposits, streams, rock uplift and falls, volcanoes, and glaciers.(1,2) The formation of the valley can be divided into four stages differentiated by exposure of granite, depth of the valley, and water features. (1) Streams were largely responsible for the deepening of the area into a valley and eroding metamorphic and sedimentary rock to reveal granite. (3) For the last 30 million years, glaciers have periodically filled much of the valley. The most current glaciation, the Wisconsinian was not, however, the most severe. Ice ages previous to the Wisconsinian were colder and lasted longer. Their glaciers were huge and covered nearly all the landmarks around Yosemite Valley except Half Dome, Eagle Peak, Sentinel Dome, and the top of El Capitan. Wisconsinian glaciers, however, only reached Bridalveil Fall in the valley.
After the retreat of many of these glaciers, a stand of Ancient Lake Yosemite developed. The valley floor owes its flatness to sediment deposited by these stands (the last glaciers in the valley were small and did not remove much old lake sediment). The last stand of Lake Yosemite was about long and was impounded by a terminal moraine near the base of El Capitan. It was later filled by sediment, becoming a swampy meadow.
The parallel Tenaya Canyon and Little Yosemite Canyon glaciers were, at their largest, deep where they flowed into the Yosemite Valley near the base of Half Dome. They also formed Clouds Rest behind Half Dome as an arête.
Near Glacier Point there are of mostly glacial sediment with at least six separate sequences of Lake Yosemite sediments. Here, huge and highly erosive pre-Wisconsinian glaciers excavated the bedrock valley floor, and much smaller Wisconsinian glaciers deposited glacial debris.
Ecology
The biological community of Yosemite Valley is a diverse one. The valley can be divided into two regions, the lower mountain forest with hot, dry summers and cool, moist winters where there can be a couple feet of snow fall, and the upper mountain forest with short moist summers and cool wet winters with snow lasting from November through June.
The animals that make up the community include various birds, mammals, fish, amphibians, reptiles, and insects. There are over 142 species of birds, prominently the California Warbler, Western Robin, and the Western Chipping Sparrow. There are approximately 90 species of mammals including shrews, bats, mice and rats, squirrels and chipmunks, rabbits, bears, large cats, and foxes. Few reptiles and amphibians are in the area due to the altitude. There are several animals that are listed as threatened species such as the Sierra Nevada red fox, Wolverine, Sierra Nevada bighorn sheep, and the pacific fisher.
Many plants have been identified in Yosemite Valley ranging from wildflowers to trees. Common trees in the area include the California Black Oak, Ponderosa Pine, Incense Cedar, Red Fir, Lodgepole Pine, Jefferey Pine, and Western Juniper. Sugar pine, white fir, interior live oak, coast Douglas-fir, California laurel, bigleaf maple, Scouler's willow, Pacific dogwood, white alder, and western balsam poplar can also be found.
Shrubs commonly found in the area include whiteleaf manzanita, mountain misery, western azalea, American dogwood, buckbrush, deer brush, sierra gooseberry.
Many wildflowers can be found throughout the year, but are most prominent from June through August. Prevalent wildflowers include the Sierra Lessingia, Monkey Flower, Beardtongue, Parasitic flowers, Shooting Stars, Lupines, and Buttercups. Other forms of flora include those of the Buckwheat, Purslane, Pink, Mustard, Pea, Evening Primrose, Mint, Figwort, and Composite families.
Tourism
Yosemite National Park had a record number of 5 million visitors in 2016. In 2020 visitation dropped to 2,268,313 visitors. A reservation system was implemented in 2020, which required a reservation in order to enter the park. The reservation system has been periodically lifted and reimplemented since 2021.
On July 24, 2018, several areas of the park, including the Valley, were closed due to wildfires in the area.
Hiking
Several trails lead out of the Valley, including The John Muir Trail – running to Mount Whitney The Mist Trail – with views of Vernal Fall and Nevada Fall The Four Mile Trail – leading to Glacier Point. The Yosemite Falls Trail – to the top of Yosemite Falls
Climbing Yosemite is now a world rock climbing attraction. The massive 'big walls' of granite have been climbed countless times since the 1950s and have pushed climbers' abilities to new heights. While climbers traditionally take several days to climb the monoliths, bivvying on the rock faces, modern climbing techniques help climbers ascend the cliffs in mere hours. Many climbers stay at Camp 4 before beginning big wall climbs, which became notable after World War II as "a birthplace of rock climbing’s modern age" and was introduced into the National Register of Historic Places in 2003.
Half Dome figures prominently on the reverse side of the California state quarter. Hiking to the top of Half Dome is one of the most popular hikes from the valley, and very crowded. In 2010 the park shifted to permit system, where hikers would apply for a permit and get assigned a day where they could do the hike.
History
Native Americans in Yosemite
Habitation of the Yosemite Valley proper can be traced to about 3,000 years ago when vegetation and game in the region was similar to that present today; the western slopes of the Sierra Nevada had acorns, deer, and salmon, while the eastern Sierra had pinyon nuts and obsidian.