Pyramid Lake (Nevada)

Pyramid Lake (Nevada)
Lake
Pyramid Lake
Name origin: pyramidal limestone columns
Country	United States
State	Nevada
Elevation	3,796 ft (1,157 m)
Coordinates	40.0624°N 119.5635°W / 40.0624; -119.5635
Length	29.8 mi (48 km)
Width	8.7 mi (14 km)
Area	188 sq mi (487 km2)
Code	856349
Volume	23,660,000 acre feet (29.18 km3)
Nevada Historical Marker
Reference No.	18

Pyramid Lake is the geographic sink of the Truckee River Basin and is located 40 mi (64 km) northeast of Reno. The inflow is moderately high silt-loaded surface runoff.

Pyramid Lake is fed by the Truckee River , which is mostly the outflow from Lake Tahoe. The Truckee River enters Pyramid Lake at its southern end. Pyramid Lake has no outlet, with water leaving only by evaporation, or sub-surface seepage (an Endorheic lake). The lake has about 10% of the area of the Great Salt Lake, but it has about 25% more volume. The salinity is approximately 1/6 that of sea water. Although clear Lake Tahoe forms the headwaters that drain to Pyramid Lake, the Truckee River delivers more turbid waters to Pyramid Lake after traversing the steep Sierra terrain and collecting moderately high silt-loaded surface runoff.

History

A remnant of the Pleistocene Lake Lahontan (~890 feet deep), the lake area was inhabited by the 19th century Paiute, which used the Tui chub and Lahontan cutthroat trout from the lake (the former is now endangered and the latter is threatened). The lake was first mapped in 1844 by John C. Frémont, the American discoverer of the lake who also gave it its English title.

Chronology

• 1903 - Irrigation diversion of the Truckee via the Derby Dam eliminated naturally-spawning Lahontan cutthroat trout, which are now stocked.^{[citation needed]}
• 1936 - The Pyramid Lake Paiute Tribe approved their constitution and by-laws.
• 1987 - A water quality model was completed for the Truckee River.

In the 19th century two battles were fought near the lake, major actions in the Paiute War. In the 1960s a marker was placed commemorating these battles. Because of water diversion beginning in 1905 by Derby Dam, the lake's existence was threatened, and the Paiute sued the Department of the Interior. By the mid-1970s, the lake had lost 80 feet of depth, and according to Paiute fisheries officials, the life of the lake was seriously under threat. The beneficiary of the water diversion in the 1970s was a racially-exclusive sportsman's and leisure reserve used for white hunting and recreation near the town of Fallon. In the opinion of John Pilger, the irrigation scheme for which water was diverted was an economic failure.

Background

The Pyramid

The lake is the largest remnant of ancient Lake Lahontan that covered much of northwestern Nevada at the end of the last ice age. Pyramid Lake was the deepest point in Lake Lahontan, reaching an estimated 890 feet (270 m) due to its low level relative to the surrounding basins. In the 19th century the vicinity of the lake was inhabited by the Paiute. The lake is now completely within the Pyramid Lake Indian Reservation. It was first mapped in 1844 by John C. Frémont, the American discoverer of the lake who also gave it its English title.

The name of the lake comes from the impressive tufa formations nearby. The largest such formation, Anaho Island, is home to a large colony of American White Pelicans and is restricted for ecological reasons. Access to the Needles, another spectacular tufa formation at the northern end of the lake has also been restricted due to recent vandalism.

Pyramid Lake was used as a stand-in for the Sea of Galilee in the 1965 biblical film, The Greatest Story Ever Told. Also, in 1961, part of The Misfits was filmed nearby.

Fish

Major fish species include the cui-ui lakesucker, which is endemic to Pyramid Lake, the Tui chub and Lahontan cutthroat trout (the world record cutthroat trout was caught in Pyramid Lake). The former is endangered, and the latter is threatened. Both species were of critical importance to the Paiute people in pre-contact times. As they are both obligate freshwater spawners, they rely on sufficient inflow to allow them to run up the Truckee River to spawn, otherwise their eggs will not hatch. Diversion of the Truckee for irrigation since the early 20th century has reduced inflow such that it is now rarely sufficient for spawning. Due to the construction of Derby Dam in 1903 to divert water to croplands in Fallon, which lowered water levels in the lake and blocked upstream spawning runs due to a lack of fish ladders, by 1939 the Lahontan cutthroat trout (the "salmon-trout" as described by Frémont) became extinct in Pyramid Lake and its tributaries. They were replaced with hatchery trout from outside the watershed.

Lahontan cutthroat trout

However, in 1979 a remnant population of the original Pyramid Lake cutthroat trout was discovered in a small brook on Pilot Peak, on the Nevada/Utah border, by Dr. Robert Behnke of Colorado State University while he was looking for the Bonneville cutthroat trout, another subspecies of the cutthroat trout. The fish were tiny and in poor condition, but Behnke identified the fingerlings as the missing Pyramid Lake variety. Subsequent DNA testing of a museum specimen has shown his identification to be correct. The fish had apparently been dumped in the creek in the early 20th century. A brood stock was raised at the U.S. Fish and Wildlife Service's Lahontan National Fish Hatchery in Gardnerville, Nevada and a successful reintroduction effort was mounted by the USFWS and the Pyramid Lake Paiute Tribe. As of 2013, twenty-pound Pyramid Lake Lahontan cutthroat trout are again being caught from the Lake's waters. The fish are doing very well, according to the USFWS project head Lisa Heki, and the 1925 record of 41 pounds may eventually be surpassed. The fish have also been placed in California's Fallen Leaf Lake, upstream of Pyramid Lake, and elsewhere. Fish populations are now sustained by several tribally-run fish hatcheries and state and federal agencies. The Pyramid Lake Lahontan cutthroat trout is the largest inland trout species in the world.^{[citation needed]}

Water quality

Because of the endangered species present and because the Lake Tahoe Basin comprises the headwaters of the Truckee River, Pyramid Lake has been the focus of several water quality investigations, the most detailed starting in the mid-1980s. Under direction of the U.S. Environmental Protection Agency, a comprehensive dynamic water quality computer model, the DSSAM Model was developed to analyze impacts of a variety of land use and wastewater management decisions throughout the 3,120-square-mile (8,100 km²) Truckee River Basin. Analytes addressed included nitrogen, reactive phosphate, total dissolved solids, dissolved oxygen and nine other parameters. Based upon use of the model, some decisions have been influenced to enhance Pyramid Lake water quality and aid the viability of Pyramid Lake biota.

See also

• Black Rock Desert
• Carson Sink
• Honey Lake
• Humboldt Sink
• Smoke Creek Desert
• Walker Lake