Lake Tahoe is a major tourist attraction in both Nevada and California. More than 75% of the lake's watershed is national forest land, covered by the Lake Tahoe Basin Management Unit of the United States Forest Service. The area surrounding the lake is also referred to as Lake Tahoe, or simply Tahoe its English name is derived from its Washo name, Dáʔaw. It is known for the clarity of its water and the panorama of surrounding mountains on all sides. The lake was formed about two million years ago as part of the Lake Tahoe Basin, and its modern extent was shaped during the ice ages. Its depth is 1,645 ft (501 m), making it the second deepest in the United States after Crater Lake in Oregon (1,949 ft or 594 m). Lying at 6,225 ft (1,897 m) above sea level, Lake Tahoe is the largest alpine lake in North America, and at 122,160,280 acre⋅ft (150.7 km 3) it trails only the five Great Lakes as the largest by volume in the United States. Lake Tahoe ( / ˈ t ɑː h oʊ/ Washo: Dáʔaw) is a freshwater lake in the Sierra Nevada of the Western United States, straddling the border between California and Nevada. The Sierra Nevada of the U.S., along the state line of California and Nevadaģ6 cu mi (150 km 3 120,000,000 acre⋅ft) ġ Shore length is not a well-defined measure.