About Lake Tahoe
The Lake Tahoe Basin was formed by geologic block faulting over 2 million years ago. A geologic block fault is a fracture in the Earth's crust that causes large blocks of land to move up or down. These uplifted blocks created what is now the Carson Range on the east side of the lake, and the Sierra Nevada mountains on the west side. Geologic blocks that dropped down created the Lake Tahoe Basin in between the two mountain ranges. The highest peak of the Lake Tahoe Basin is Freel Peak, which stands at 10,891 ft. Heavenly Ski Area (Monument Peak) is 10,067 ft. The lake itself sits at 6,200 feet.
Snow, rain, and streams filled the southern and lowest part of the basin, forming the ancestral Lake Tahoe. Modern Lake Tahoe was shaped and landscaped by the scouring glaciers during the Ice Age (the Great Ice Age began a million or more years ago). Many streams flow into Lake Tahoe, but the lake is drained only by the Truckee River, which flows northeast through Reno and into Pyramid Lake in Nevada.
Lake Tahoe is the second deepest lake in the United States and the tenth deepest in the world, with a maximum depth measured at 1,645 ft, average depth of 1,000 ft. Crater Lake in Oregon is the deepest lake (1,949 ft or 594 m) in the United States.
Lake Tahoe is about 22 miles long and l2 miles wide and has 72 miles of shoreline. This gives a surface area of 191 miles. With an average surface elevation of 6,225 ft above sea level, Lake Tahoe is the highest lake of its size in the United States.
The water temperature near the surface generally cools to 40 to 50oF (4.5 to 10oC) during February and March and warms to 65 to 70oF (18 to 21oC) during August and September. Below a depth of 600 to 700 ft (183 to 213 m), the water temperature remains a constant 39oF (4.0oC). For current water temperatures and conditions, visit the Tahoe Diving page at Sierra Diving Center.
Lake Tahoe has a water clarity of about 70 feet. The clarity has reduced from greater than 100 feet since readings began in the late 1960's.
