Yosemite National Park is located in the central Sierra Nevada of California, at the eastern portions of Tuolumne, Mariposa, and Madera counties in east central of California. The park covers an area of 3,081 km² and reaches across the western slopes of the Sierra Nevada mountain chain. The park is approximately the size of Rhode Island State.
Yosemite was made during the last Ice Age . The granite bedrock was turned into bare peaks, sheer cliffs, rounded domes and huge monoliths. Yosemite is one of the largest and least fragmented habitat blocks in the Sierra Nevada. Now flowering meadows fill the valley and beautiful waterfalls surround it.
Geological evolution, and Biological adaptation is evident. Breathtaking panoramas of rugged scenery, thousands of lakes, 2,600 km of streams, 1300 km of hiking trails, 560 km of roads, and huge variety of plant and animal life are incomparable this valley.
The park has an elevation range from 600 to 4,000 m. and contains five major vegetation zones: wooded area of oak trees, groves of low mountains, high mountain vegetation, sub alpine vegetation, and alpine vegetation. Of California's 7,000 plant species, about 50% is in the Sierra Nevada and more than 20% within Yosemite.
Elsewhere in Yosemite National Park has vast areas of unspoilt and sometimes inaccessible wilderness, as is the case with Kings Canyon and Sequoia, the other national parks in Sierra Nevada.
There are three groves of giant sequoia trees, two near Crane Flat, but the most famous is the Mariposa Grove of Big Trees in the southwest corner, near the private village of Wawona.
Another gigantic type of tree is the Grizzly Giant, estimated for having almost 3,000 years old, in the park exist more than 400 trees of this type that grow on the hillsides.
The weather can be moderately warm and dry through the summer, but nights may be cool. In the winter, it can be rather cold with frequent snowfalls that sometimes create dangerous driving conditions. Tioga Pass and the higher elevations of the park are normally closed from November through May due to heavy snow accumulation. Spring and fall are transition periods that rotate between nice weather and wet or snowy conditions.
Summer offers the warmest weather but is the busiest tourist season. Spring, with its heavy extra of snow melt offers the most spectacular waterfall show. Fall, with its multicolored foliage and usually pleasant weather is a scenic time to visit. Although winter often produces some beautiful snow covered landscapes. Independently of the station you decide to visit Yosemite, is wise to take a variety of clothes, for the constant changes in the climate.
In 1851, a battalion of Indian fighters wandered around for Yosemite's Valley and was stopped by the view. They were the first nonnative to see this landscape. Later a man who visited this valley wrote: "Nobody who has not visited this can imagine the incomparable beauty of this valley”.
Efforts to protect Yosemite Valley began in June 30, 1864, when President Abraham Lincoln signed a law granting Yosemite Valley and the Mariposa Grove of Giant Sequoias to the State of California as inalienable land. This was the first time in history that a federal government had set aside scenic lands simply to protect them and to allow for their enjoyment by all people.
The area became a national park in October 1, 1890 following several years of struggle by John Muir against the devastation of the sub alpine meadows surrounding Yosemite Valley.
Despite its national park status, California controlled the initial grant area until 1906. Prior to ceding control to the city of San Francisco, became embroiled in a bitter political struggle over the Hetch Hetchy Valley, in which the city wanted to dam the Tuolumne River as a source of drinking water and hydroelectric power.
In 1913, conservationists led by John Muir lost the battle when Congress passed the Raker Act, authorizing the construction of O'Shaughnessy Dam. This day crusades to restore Hetch Hetchy were ongoing. John Muir said: "The construction of a dam provides the drinkable water for the people of San Francisco, but the dam was causing floods of the of the lower reaches of the Grand Canyon of the Tuolumne River, and also it was damaging the Valley Yosemite".
Yosemite has grown; its historical meaning makes it a jewel of the System of American National Park. With 3.5 million visitors per year, makes to Yosemite the best tourist destination of the United States. Only 12 miles squared inside the valley Yosemite can be visited (about 1% of the total park land).
The dual role of the park service is protecting the resource and provide for the enjoyment of the visitor. Yosemite continues to be an important breeding ground for management ideas about US National Parks.
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.