Yosemite Valley a National Historic District and as a California Historical Landmark. After the creation of the Park Service, many separate hotel owners held separate concession contracts. The Yosemite Park Company had built the Yosemite Lodge and Yosemite Village had its own group of merchants. Fire had destroyed a number of the original valley hotels and concession owners came and went until Park Service forced the two largest companies to merge in order that one single concession contract could be given. In 1925 the two family-run companies became the Yosemite Park and Curry Company and went on to build and run the
Yosemite National Park 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. 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