Mount Whitney is the highest summit in the contiguous United States and the Sierra Nevada, with an elevation of 14,505 feet (4,421 m). It is on the boundary between California’s Inyo and Tulare counties, 85 west-northwest of the lowest point in North America at Badwater Basin in Death Valley National Park at 282 ft (86 m) below sea level. The west slope of the mountain is in Sequoia National Park and the summit is the southern terminus of the John Muir Trail which runs 211.9 mi (341.0 km) from Happy Isles in Yosemite Valley. The east slope is in the Inyo National Forest in Inyo County.

In July 1864, the members of the California Geological Survey named the peak after Josiah Whitney, the State Geologist of California and benefactor of the survey.[7] During the same expedition, geologist Clarence King attempted to climb Whitney from its west side, but stopped just short. In 1871, King returned to climb what he believed to be Whitney, but having taken a different approach, he actually summited nearby Mount Langley. Upon learning of his mistake in 1873, King finally completed his own first ascent of Whitney, but did so a month too late to claim the first recorded ascent.[21] Just a month earlier, on August 18, 1873, Charles Begole, A. H. Johnson, and John Lucas, all of nearby Lone Pine, had become the first to reach the highest summit in the contiguous United States.