Lake Tahoe is a large freshwater lake in the Sierra Nevada of the United States.
Lying at 6,225 ft, it straddles the state line between California and Nevada, west of
Carson City.
Lake Tahoe is the largest alpine lake in North America, and at 122,160,280 acre-ft it trails
only the five Great Lakes as the largest by volume in the United States.
Its depth is 1,645 ft, making it the second deepest in the United States after Crater
Lake in Oregon 1,949 ft.
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.
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.
More than 75% of the lake's watershed is national forest land, being the Lake Tahoe Basin Management
Unit of the United States Forest Service.
Lake Tahoe is a major tourist attraction in both Nevada and California.
It is home to winter sports, summer outdoor recreation, and scenery enjoyed throughout
the year.
Snow and ski resorts are a significant part of the area's economy and reputation.
The Nevada side also offers several lakeside casino resorts, with highways providing year-round
access to the entire area.
Lake Tahoe is the second deepest lake in the U.S, with a maximum depth of 1,645 feet, trailing
Oregon's Crater Lake at 1,949 ft.
Tahoe is the 16th deepest lake in the world, and the fifth deepest in average depth.
It is about 22 mi long and 12 mm wide and has 72 mi of shoreline and a surface area
of 191 square miles.
The lake is so large that its surface is noticeably convex due to the curvature of the earth.
At lake level, the opposing shorelines are below the horizon at its widest parts; by
nearly 100 feet at its maximum width, and by some 320 feet along its length.
Visibility may vary somewhat with atmospheric refraction; when the air temperature is much
greater than the lake temperature, looming may occur where the lake surface or opposing
shoreline is lifted above the horizon.
Fata Morgana may be responsible for Tahoe Tessie sightings.
Approximately two-thirds of the shoreline is in California.
The south shore is dominated by the lake's largest city, South Lake Tahoe, California,
which adjoins the town of Stateline, Nevada, while Tahoe City, California, is located on
the lake's northwest shore.
Although highways run within sight of the lakeshore for much of Tahoe's perimeter, many
important parts of the shoreline lie within state parks or are protected by the United
States Forest Service.
The Lake Tahoe Watershed of 505 sq mi includes the land area that drains to the lake and
the Lake Tahoe drainage divide traverses the same general area as the Tahoe Rim Trail.
Lake Tahoe is fed by 63 tributaries.
These drain an area about the same size as the lake and produce half its water, the other
half by direct precipitation.
The Truckee River is the lake's only outlet, flowing northeast through Reno, Nevada, into
Pyramid Lake which has no outlet.
It accounts for one-third of the water that leaves the lake, the rest evaporating from
the lake's vast surface.
The flow of the Truckee River and the height of the lake are controlled by the Lake Tahoe
Dam at the outlet.
The natural rim is at 6,223 ft above sea level.
The maximum legal limit to which the lake can be allowed to rise in order to store water
is 6,229.1 ft; a spillway at the dam controls overflow.
Around New Year 1996/1997 a Pineapple Express atmospheric river melted snow and caused the
lake and river to overflow, inundating Reno and surrounding areas.
The Lake Tahoe Basin was formed by vertical motion faulting.
Uplifted blocks created the Carson Range on the east and the main Sierra Nevada crest
on the west.
Down-dropping and block tilting created the Lake Tahoe Basin in between.
This kind of faulting is characteristic of the geology of the adjoining Great Basin to
the east.
Lake Tahoe is the youngest of several extensional basins of the Walker Lane deformation zone
that accommodates nearly 0.47 in per year of dextral shear between the Sierra Nevada-Great
Valley Block and North America.
Three principal faults form the Lake Tahoe basin: the West Tahoe Fault, aligned between
Meyers and Tahoe City, which is the local segment of the Sierra Nevada Fault, extending
onshore north and south of these localities; the Stateline/North Tahoe Fault, starting
in the middle of the lake and creating the relief that forms Stateline, NV; and the Incline
Village Fault, which runs parallel to the Stateline/North Tahoe Fault offshore and into
Incline Village.
The West Tahoe Fault appears to be the most active and potentially hazardous fault in
the basin.
A study in Fallen Leaf Lake, just south of Lake Tahoe, used seafloor mapping techniques
to image evidence for paleo earthquakes on the West Tahoe and revealed the last earthquake
occurred between 4,100 and 4,500 years ago.
Subsequent studies revealed submarine landslides in Fallen Leaf Lake and Lake Tahoe that are
thought to have been triggered by earthquakes on the West Tahoe fault and the timing of
these events suggests a recurrence interval of 3,000–4,000 years.
Some of the highest peaks of the Lake Tahoe Basin that formed during the process of Lake
Tahoe creation are Freel Peak at 10,891 feet, Monument Peak at 10,067 feet, Pyramid Peak
at 9,984 feet and Mount Tallac at 9,735 feet.
The north shore boasts three peaks at over 10,000 feet: Mount Rose at 10,785 feet, and
Houghton and Relay peaks.
Mt.
Rose is a very popular hiking and backcountry skiing destination.
Eruptions from the extinct volcano Mount Pluto formed a volcanic dam on the north side.
Melting snow filled the southern and lowest part of the basin to form the ancestral Lake
Tahoe.
Rain and runoff added additional water.
The Sierra Nevada adjacent to Lake Tahoe was carved by scouring glaciers during the Ice
Ages, which began a million or more years ago and retreated ~15,000 years ago at the
end of the Pleistocene.
The glaciers carved canyons that are today iconic landmarks such as Emerald Bay, Cascade
Lake, and Fallen Leaf Lake, among others.
Lake Tahoe itself never held glaciers, but instead, water is retained by damming Miocene
volcanic deposits.
Soils of the basin come primarily from andesitic volcanic rocks and granodiorite, with minor
areas of metamorphic rock.
Some of the valley bottoms and lower hill slopes are mantled with glacial moraines or
glacial outwash material derived from the parent rock.
Sandy soils, rock outcrops and rubble, and stony colluvium account for over 70% of the
land area in the basin.
The basin soils are generally 65–85% sand.
Given the great depth of Lake Tahoe and the locations of the normal faults in the deepest
portions of the lake, modeling suggests that earthquakes on these faults can trigger tsunamis.
Wave heights of these tsunamis are predicted to be on the order of 10 to 33 ft in height,
capable of traversing the lake in just a few minutes.
A massive collapse of the western edge of the basin that formed McKinney Bay around
50,000 years ago is thought to have generated a tsunami wave with a height approaching 330
ft . Lake Tahoe has a dry-summer continental climate, featuring warm, dry summers and chilly
winters with regular snowfall.
Mean annual precipitation ranges from over 55 inches for watersheds on the west side
of the basin to about 26 inches near the lake on the east side of the basin.
Most of the precipitation falls as snow between November and April, although rainstorms combined
with rapid snowmelt account for the largest floods.
There is a pronounced annual runoff of snowmelt in late spring and early summer, the timing
of which varies from year to year.
In some years, summertime monsoon storms from the Great Basin bring intense rainfall, especially
to high elevations on the northeast side of the basin.
August is normally the warmest month at the Lake Tahoe Airport with an average maximum
of 78.7 °F and an average minimum of 39.8 °F. January is the coolest month with an
average maximum of 41.0 °F and an average minimum of 15.1 °F. The all-time maximum
of 99 °F was recorded on July 22, 1988.
The all-time minimum of −16 °F was recorded on December 9, 1972.
Temperatures exceed 90 °F on an average of 2 days annually.
Minimum temperatures of 32 °F or lower occur on an average of 231 days annually, and minimum
temperatures of 0 °F or lower occur on an average of 7 days annually.
Freezing temperatures have occurred in every month of the year.
The area around Lake Tahoe was previously inhabited by the Washoe Native Americans.
Lake Tahoe was the center and heart of Washoe Indian territory, including the upper valleys
of the Walker, Carson, and Truckee Rivers.
Cave Rock is a large rock formation located on the southeastern shore of the lake and
considered a sacred site for the Washoe Indians.
The Washoe people called Cave Rock.
Part of why the Washoe felt the Cave was sacred was due to "The Lady of the Lake" a rock formation
on the side of the Cave which looks like the profile of a woman's face gazing out towards
the lake.
Washoe ancestors performed religious ceremonies inside the cave.
There were significant but ultimately unsuccessful protests from the tribe when a tunnel was
blasted through the rock in 1931 for Highway 50.
Despite land-use planning and export of treated sewage effluent from the basin, the lake is
becoming increasingly eutrophic with primary productivity increasing by more than 5% annually,
and clarity decreasing at an average rate of 0.82 feet per year.
Until the early 1980s, nutrient-limitation studies showed that primary productivity in
the lake was nitrogen-limited.
Now, after a half-century of accelerated nitrogen input, the lake is phosphorus-limited.
Theodore Swift concluded that "suspended inorganic sediments and phytoplanktonic algae both contribute
significantly to the reduction in clarity, and that suspended particulate matter, rather
than dissolved organic matter, are the dominant causes of clarity loss."
The largest source of fine sediment particles to Lake Tahoe is urban stormwater runoff,
constituting 72 percent of the total fine sediment particle load.
Recent research has shown that the urban uplands also provide the largest opportunity to reduce
fine sediment particles and phosphorus contributions to the lake.
Historic clarity of approximately 98 feet can be achieved with a total reduction of
approximately 75 percent from urban sources.
Historically, the clarity of Lake Tahoe continued to decrease through 2010, when the average
Secchi depth, 64.4 feet, was the second-lowest ever recorded.
This represented a decrease of 3.7 feet from the previous year.
However, the lake's clarity increased from 2011 to 2014, improving by nearly 20 percent.
Much of the area surrounding Lake Tahoe is devoted to the tourism industry and there
are many restaurants, ski slopes, golf courses, and casinos catering to visitors.
During ski season, thousands of people from all over Nevada and California, including
Reno, Las Vegas, Los Angeles, San Diego, San Francisco, and Sacramento, flock to the slopes
for downhill skiing.
Lake Tahoe, in addition to its panoramic beauty, is well known for its blizzards.
Many ski areas around Tahoe also have snow tubing, such as Squaw Valley.
Throughout Tahoe, cross-country skiing, snowmobile riding, and snowshoeing are also popular.
From late Spring to early Fall, the lake is popular for water sports and beach activities.
The two cities most identified with the Lake Tahoe tourist area are South Lake Tahoe, California,
and the smaller Stateline; smaller centers on the northern shoreline include Tahoe City
and Kings Beach.
Other popular activities include parasailing, jet ski rentals, eco-friendly paddle sport
rentals, and fishing.
There are rental locations around Lake Tahoe.
Kayaking and stand-up paddleboards have also become very popular.
Boating is a primary activity in Tahoe in the summer.
The lake is home to one of the most prestigious wooden boat shows in the country, the Lake
Tahoe Concours d'Elegance, held every August.
There are lakefront restaurants all over the lake, most equipped with docks and buoys.
There are all sorts of boating events, such as sailboat racing, firework shows over the
lake, guided cruises, and more.
As an interstate waterway, Lake Tahoe is subject to the United States Coast Guard.
Lake Tahoe is home to Coast Guard Station.
SCUBA diving is popular at Lake Tahoe, with some dive sites offering dramatic drop-offs
or wall dives.
Diving at Lake Tahoe is considered advanced due to the increased risk of decompression
sickness while diving at such a high altitude.
The lake and its scenic environs provide many opportunities for motorcyclists to ride both
on and off-road.
The most popular circuit that goes around the lake runs clockwise and starts in South
Lake Tahoe on the California side.
Riding north via route 89 allows riders to pull over to the right to admire the views
without crossing traffic.
Continuing onto highway 28 East, and finally, onto US-50 West will complete the full tour.
There are numerous hiking and mountain biking trails around the lake.
They range widely in length, difficulty, and popularity.
One of the most famous of Tahoe's trails is the Tahoe Rim Trail, a 165-mile trail that
circumnavigates the lake.
Directly to the west of the lake is the Granite Chief Wilderness, which provides great hiking
and wilderness camping.
Also, to the southwest is the very popular Desolation Wilderness.
One of the most popular trailheads used to access these popular destinations is Eagle
Lake trailhead, located near Emerald Bay on Tahoe's west shore.
Gambling is legal on the Nevada side of Lake Tahoe.
Casinos, each with a variety of slot machines and table games, are located on the South
Shore in Stateline, and on the North Shore in Crystal Bay and Incline Village.
Lake Tahoe can be reached directly by car, and indirectly by train or air.
The nearest passenger train service is the Amtrak station in Truckee and is served by
Amtrak's train, the California Zephyr, which runs daily between Chicago and the San Francisco
Bay Area.
The closest scheduled passenger airline service is available via the Reno-Tahoe International
Airport.
South Tahoe Area Transit Authority is the primary mass, transportation provider.
Visitors can reach Lake Tahoe under ideal conditions within two hours from the Sacramento
area, one hour from Reno, or thirty minutes from Carson City.
In winter months, chains or snow tires are often necessary to reach Tahoe from any direction.
Traffic can be heavy on weekends due to tourists if not also from the weather.