Lake Tahoe is a large freshwater lake in the Sierra Nevada of the United States. At a surface elevation of 6,225 ft, it is located along the border between California and Nevada, west of Carson City. Lake Tahoe is the largest alpine lake in North America. Its depth is 1,645 ft, making it the second-deepest in the United States (the deepest is Crater Lake in Oregon, being 300 ft deeper, at 1,945 ft). Additionally, Lake Tahoe is listed as the 26th largest lake by volume in the world at 122,160,280 acre·ft (150.68249 km3). The lake was formed about 2 million years ago and is a part of the Lake Tahoe Basin with the modern lake being shaped during the ice ages. It is known for the clarity of its water and the panorama of surrounding mountains on all sides. The area surrounding the lake is also referred to as Lake Tahoe, or simply Tahoe.