thundering waterfalls that are among the world’s highest.

Yosemite was the birthplace of the idea of the Sierra Club and plays an important role in wildlife preservation and preserving biological diversity.

The park is a world heritage site which has made a significant contribution to California’s cultural heritage, to the national park movement, and to Yosemite’s 4,000 years of cultural heritage by Native Americans.

History
While man has lived in Yosemite for thousands of years, the park’s human history is far shorter than its geological history.

At one time, this area was made up of gentle rolling hills, crisscrossed with a maze of stream systems. Millions of years ago, California’s Sierra Nevada was formed by a gradual series of earth upheavals. As the mountains rose, the land tilted and the westward flowing Merced River accelerated, carving deep, v-shaped river canyons. Later, massive glaciers flowed down the canyons. Colder temperatures slowed melting and eventually glaciers formed and began to carve away at the v-shaped canyons, transforming them into u-shaped valleys.

Tributary streams did not carve their canyons as deep as Merced Canyon. Glaciers sheared off these canyons leaving them as “hanging valleys.” Tributary creeks, which had once joined the main stream at the same elevation, now plummeted off of shear cliffs, giving birth to the park’s famed waterfalls.

Eventually, sediment washed down out of the high country, filled in Lake Yosemite to form the present valley floor.

The area’s first residents were Native Americans who inhabited the region perhaps as long ago as 7,000 to 10,000 years.

Various tribes lived in the area over the years, the most recent of which was a Miwok tribe that called Yosemite Valley Ahwahnee which is believed to mean, “place of the gaping mouth.” They referred to themselves as the Ahwahneechee.

By 1855, the first party of tourists arrived and nine years later, encouraged by a group of influential Californians, Abraham Lincoln signed the Yosemite Grant which set aside Yosemite Valley and the Mariposa Grove of Giant Sequoias as a state supervised public reserve.

Size and Visitation
Yosemite National Park embraces almost 1,200 square miles of scenic wild lands set aside in 1890 to preserve a portion of the central Sierra Nevada that stretches along California’s eastern flank. The park ranges from 2,000 feet above sea level to more than 13,000 feet and has these major attractions; alpine wilderness, three groves of Giant Sequoias and the glacially carved Yosemite Valley with impressive waterfalls, cliffs and unusual rock formations.

Giant Sequoia Groves
The Mariposa Grove, 35 miles south of Yosemite Valley, is the largest of three Sequoia groves in Yosemite. The Tuolumne and Merced Groves are near Crane Flat. Despite human pressures, these towering trees, largest of all living things, have endured for thousands of years. Only in recent years, however, have we begun to understand the Giant Sequoia environment.

Sequoias are wonderfully adapted to fire. The wood and bark are fireresistant.

Black scars on a number of large trees that are still prospering indicate they have survived many scorching fires. Sequoia reproduction also depends on fire. As you look at these trees, keep in mind that they have been here since the beginning of history in the western world.

The Mariposa Grove’s Grizzly Giant is 2,700 years old and is thought to be the oldest of all Sequoias.

Yosemite Valley
“The Incomparable Valley”, it has been called, is probably the world’s best known example of a glacier-carved canyon. Its leaping waterfalls, towering cliffs, rounded domes, and massive monoliths make it a preeminent natural marvel. These attributes have inspired poets, painters, photographers, and millions of visitors beginning with John Muir for more than one hundred years. Nowhere in Yosemite is the sense of scale so dramatic.

Yosemite Valley is characterized by sheer walls and a flat floor. Its evolution began when alpine glaciers lumbered through the canyon of the Merced River. The ice carved through weaker sections of granite plucking and scouring rock but leaving harder, more solid portions—such as El Capitan and Cathedral Rocks—intact and greatly enlarging the canyon that the Merced River had
carved through successive uplifts of the Sierra.

Finally the glacier began to melt and the terminal moraine left by the last glacial advance into the valley dammed the melting water to form ancient Lake Yosemite, which sat in the newly carved U-shaped valley. Sediment eventually filled in the lake, forming the flat valley floor you see today. This same process is now filling Mirror Lake at the base of Half Dome.

In contrast to the valley’s sheer walls, the Merced Canyon along California 140 outside the park is a typical river-cut, V-shaped canyon, for the glaciers did not extend this far. Back from the rim of the valley itself, forested slopes show some glacial polish. But for the most part these areas also were not glaciated.

The valley is a mosaic of open meadows sprinkled with wildflowers and flowering shrubs, oak woodlands, and mixed-conifer forests of ponderosa pine, incense-cedar, and Douglas-fir. Wildlife from monarch butterflies to mule deer and black boars flourishes in these communities. Around the valley’s perimeter, waterfalls, which reach their maximum flow in May and June, crash to the floor. Yosemite, Bridalveil, Vernal, Nevada, and Illilouette are the most prominent of these falls, some of which have little or no water from mid-August through early fall.

Yosemite’s Wildlife
Yosemite National Park is home to 300 - 500 American black bears, Ursus americanus. Although usually referred to as the black bear, very few are black, and they are more likely to be found in a variety of colors ranging from black to brown, blond, or cinnamon.

Black bears are omnivores and will eat almost anything. They spend most of their days foraging for grasses, seeds, berries, acorns, and insects and occasionally feed on carrion. Bears tear open rotten logs or old stumps in search of insect larvae. The goal of wildlife managers is to provide the park’s black bears a home where they can thrive in a natural condition, dine on native plants and animals, and reach a normal life expectancy.

To achieve this, one thing must happen in Yosemite: all human food, scented items, and garbage must be properly stored where bears cannot get them. This goal has been made possible with the help of the Yosemite Fund, which over the past 10 years, has donated food storage lockers for every park campsite, trailhead, parking lot, and rental tent camp. Since 1999, incidences of bears obtaining human food have plummeted, in large part because of increased cooperation of park visitors in storing their food and trash properly.

On the other hand the California Bighorn Sheep, the Golden Eagle, the great gray owl, the silver grey coyote, the mule deer, squirrels, the Steller´s Jay and the peregrine falcon, find in Yosemite´s Park a shelter and a way to survive to the enormeous press ure that we human put on to mother nature today.