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LAKE TAHOE AT A GLANCE

• Surface Elevation: 6,225 ft

• Length: 22 miles

• Width: 12 miles

• Average Depth: 1,000 ft

• Maximum Depth: 1,645 ft

• Volume: 39 trillion gallons

• Watershed Area: 314 sq. mi.

• Shoreline: 72 miles

How the lake was formed

The Lake Tahoe Basin was formed by faulting (fractures in the earth’s crust allowing blocks of land to rise and sink) occurring over several million years. A fault on the eastern margin created the Carson Range, while the Sierra Nevada rose out of a shallow sea on the western side. The movement of rock and earth created the high peaks of the Tahoe Basin, along with Lake Tahoe.

The Tahoe Basin is mostly granite, with little topsoil, and therefore few nutrients have washed into the lake to promote the growth of algae and other organisms that make water murky.

As well, 40 percent of the precipitation falling into the Lake Tahoe Basin, lands directly on the lake. The remaining precipitation drains through the decomposed granite soil found in marshes and meadows, creating a good filtering system for water.

Tahoe’s native peoples

The Washoe are the native peoples to Lake Tahoe. They once wintered in the Carson Valley and spent their summers on the shores of the lake hunting, fishing and gathering foods for the winter. Today, the Washoe are working to reclaim some of their native lands.

Lake Tahoe’s discovery

The first recorded discovery of Lake Tahoe by white explorers was on Feb. 14, 1844, when John Charles Frémont and Charles Preuss spotted the lake from atop Red Lake Peak. Frémont named the lake “Mountain Lake” and then called it “L. Bonpland,” in honor of French botanist Aimé Jacques Alexandre Bonpland. The name was changed to Lake Bigler in 1857 in honor of Calif. Gov. John Bigler. The lake was renamed Tahoe in 1945.

Tahoe is a mispronunciation of the first two syllables of the Washoe’s word for the lake – Da ow a ga, which means “edge of the lake.”

About the lake

Lake Tahoe is located along the states of California and Nevada, with two-thirds in California. It is fed by 63 streams and two hot springs.

The Truckee River is Tahoe’s only outlet and flows from the dam in Tahoe City east through Reno and eventually drains into Pyramid Lake in the Nevada desert. From there, it evaporates into the atmosphere.

By law, the lake’s surface elevation cannot exceed 6,229.1’, so it’s kept at the level or lower by releasing water into the Truckee River at the dam in Tahoe City.

However, water releases are not permitted when the lake surface level falls below the natural rim at 6,223.’ The lowest lake level on record (measured since 1900) was 6,220.26’ on Nov. 30, 1992.

Lake clarity

The University of California, Davis, operates the Tahoe Environmental Research Center, which monitors, among other things, the clarity of Lake Tahoe.

Clarity has been measured since 1968 using a Secchi measurement, which is the point below the lake surface at which a 10” white disk disappears from view). The annual Secchi depth is composed of about 25 readings throughout the year.

In 2006, the Secchi depth was 67.7’, a reduction of 4.6’ from the previous year.

Interesting facts

• Lake Tahoe is the largest alpine lake in North America and the second deepest lake in the U.S. (Crater Lake in Oregon, at 1,932 feet, is deeper). It is the eighth deepest in the world.

• If Lake Tahoe was emptied, it would submerge California under 14.5” of water. There is enough water in Tahoe to supply everyone in the United States with 50 gallons of water per day for five years.

• Due to its depth, Lake Tahoe never freezes.

Sources: Tahoe Environmental Research Center, U.S. Geological Survey, National Park Service, League to Save Lake Tahoe, “Tahoe Place Names.”

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