News of its scenic beauty spread and the valley was soon the site of homes, hotels, orchards, and heavily grazed meadows. Thus, although its shape is not solely the result of glaciation, glaciers played an important part in the history of Yosemite Valley.Īlthough Yosemite Valley was no doubt known to Native Americans for centuries, it was not entered by non- Native Americans until 1851, two years after the California gold rush began in 1849. Geological Survey report that concluded Yosemite Valley owed its unique shape to a combination of glacial and river erosion of fractured rocks. The controversy was settled by a 1930 U.S. Several years of traveling through the Yosemite region, however, convinced Muir that the valley was carved by glaciation. This was in part because Whitney recognized that Yosemite was unlike the well-known glaciated valleys of Europe. Before Muir had arrived in California, prominent California geologist Josiah Whitney had visited Yosemite and inferred that the steep-walled valley was a graben, the geological term for a fault-bounded block of rock lowered relative to the blocks on either side. He was the first to suggest that Yosemite Valley is the product of glaciation. His travelogue contains a mixture of high adventure and studious observations of the flora, fauna, and geology of the Yosemite region. Likewise, his description of the history of a raindrop shows an understanding of the hydrologic cycle, particularly the role of stored groundwater in the maintenance of perennial stream flow. Muir was an amateur naturalist, and his descriptions of rocks and vegetation show a command of basic mineralogy and botany. Published in 1911, only three years before his death, Muir's My First Summer in the Sierra recalls his first trip to the range more than forty years earlier. Muir also co-founded the Sierra Club in 1892, providing a formal organization for environmental activists to continue working for the preservation of the nation's mountain ranges. His work was instrumental in the creation of the national parks, including Yellowstone, Yosemite, Mount Rainier, and Grand Canyon National Park, and his writing inspired many of the conservation programs enacted by President Theodore Roosevelt, including the first National Monuments by Presidential Proclamation. Muir feared that the United States as he had witnessed it would gradually become overdeveloped, and he wrote extensively about the importance of protecting the natural landscape and wildlife of the country. Boston: Houghton Mifflin, 1911.Ībout the Author: Naturalist John Muir (1838–1914) was a Scottish-born wilderness explorer, best known for his adventures in the glaciers of Alaska and California's Sierra Nevada.

My summer in the sierra