Maximum depth: 1,645 feet
Average depth: 1,000 feet
Maximum diameter 22 miles
Minimum diameter 12 miles
Surface area 191 sq. miles
Shoreline 72 miles
Highest peak 10,891 feet
The Lake Tahoe Basin was formed by geologic block faulting about 2 to 3 million years ago. Block faulting is a fracture in the earth’s crust causing blocks of land to move up or down. Uplifted blocks created the Carson Range on the East and the Sierra Nevada on the West. The Lake Tahoe Basin was created with down-dropped blocks.
Snow, rain, and streams filled the southern and lowest part of the basin, forming Lake Tahoe. In more modern times, Lake Tahoe was shaped and landscaped by the scouring of glaciers during the Ice Age a million or more years ago. Many streams flow into the lake, but only the Truckee River drains the lake. The Truckee River flows from Tahoe City through Truckee and Reno and into Pyramid Lake in Nevada.
The highest peaks are Freel Peak (10,891ft.), Monument Peak (Heavenly Valley Resort, 10,067ft.), Pyramid Peak (9,983ft.), and Mt. Tallac (9,735ft.).
Lake Tahoe is the second deepest lake in the US and the tenth deepest in the world. The water temperature near the surface generally cools to 40-50 degrees in winter and warms to 65-70 during August and September. Below a depth of 700 feet the water maintains a constant 39 degrees.
Lake Tahoe’s water clarity is about 64 feet currently. The clarity was recorded greater than 100 feet since readings began in the 1960’s. Water clarity is an ongoing problem that environmental and government groups continue to work on. Two major clarity problems are microscopic sediments entering the lake and algae growth fueled by nitrogen and phosphorus.