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Carson Sink

Carson Sink
View southeast across the Carson Sink from Topog Peak in the West Humboldt Range
View southeast across the Carson Sink from Topog Peak in the West Humboldt Range
The Carson Sink and the Lahontan Valley form the central portion of the lake bed of the prehistoric Lake Lahontan.
The Carson Sink and the Lahontan Valley form the central portion of the lake bed of the prehistoric Lake Lahontan.
Coordinates: 39°52′40″N 118°20′50″W / 39.87778°N 118.34722°W / 39.87778; -118.34722
LocationLahontan Basin, Nevada
Part ofCarson (40 Mile) Desert
Water bodiesNorth Carson Lake, Stillwater Marsh
Area
  Total300 sq mi (780 km2)
Dimensions
  Length32 mi (51 km)
  Width29 mi (47 km)
Surface elevation3,865 ft (1,178 m)

Carson Sink is a approximately 300 square miles (780 km2) playa next to a swampy lowland, approximately 100 sq mi (259 sq km) in the northeastern portion of the Carson Desert in present-day Nevada, United States of America, that was formerly the terminus of the Carson River. Including the sand dunes and former beaches of prehistoric Lake Lahontan, the sink is over 1000 sq mi (2600 sq km). It is located in northern Churchill County, northwest of Fallon. Today the sink is currently fed by drainage canals of the Truckee-Carson Irrigation District. The southeastern fringe of the sink, where the canals enter, is a wetland of the Central Basin and Range ecoregion characterized by shallow artificial lakes and sloughs called the Stillwater Marsh.[1]

The sink is fed by the Carson River which descends from the Sierra Nevada from the southwest. During periods of heavy rain the sink receives overflow from the nearby Humboldt Sink, which receives the Humboldt River. Rainfall in the sink averages approximately 6 in (15 cm) per year. Part of the sink is protected as part of the Fallon National Wildlife Refuge and the Stillwater Wildlife Management Area. A section of the Fallon Naval Air Station is located in the northeastern part of the sink.

The Carson Sink is geographically bounded by the West Humboldt Range to the north and the Stillwater Range to the east. To the south the land raises slightly, and is extensively farmed. To the west lies the Forty Mile Desert, so named because along that section of the Carson River Route of the California Trail one had to travel roughly forty miles between the last drinkable water on the Humboldt River to the first drinkable water on the Carson River. That was a great hardship to California bound immigrants in the 1840s and 1850s, many of whom were already near starvation by the time they reached it.

This is mostly included within the Fallon National Wildlife Refuge and the Stillwater Wildlife Management Area. This area serves as an important stopover for migrating waterfowl. The Sehoo Formation is south of the Carson Sink.[2]

Mining and human activities caused a great die off in 1987. https://ndep.nv.gov/environmental-cleanup/superfund/carson-river-mercury-superfund-site

Carson Sink and Lone Rock working areas

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The Carson Sink and Lone Rock working areas are the northwest portion of both the Carson Sink and the US Naval Fallon Range Training Complex.[3] The Lone Rock working area includes the Bravo-20 range, which has numerous targets for combat aircraft training.[3]

Lone Rock is in the middle of a Bravo-20 live bombing area.[3] It is a solitary pinnacle of rock through the playa and it is held sacred by the Northern Paiute.[4]

History

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Pre-History and Pleistocene Lake Lahontan

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The Carson Sink and Lahontan Valley formed the deep central portion of the Pleistocene water body Lake Lahontan between 45,000 and 9,000 years ago[5], the lakebed of which is now the Lahontan Basin. This Pleistocene lake varied in size between glacial periods (where it was high) and inter-glacial periods (where it was low). It had high stands around 700,000, 125,000, and 14,500-12,700 years before present (Y.B.P.) . Due to warming and climate change in the Bølling–Allerød (B-A) Period and the Clovis Drought, Lake Lahontan shrunk. By 11,000 years, Lake Lahontan in this region had shriveled into a shallow marshland to a flat. But when the Younger Dryas came, the climate became wetter and much cooler, which led to more runoff leading to the lake reaching a high stand 4,050 ft (1,235 m). Beach ridges dating from the Younger Dryas show that large lakes occupied the basin during that time.[6]

Following that, the Altithermal, lasting from 7,500-4,500 Y.B.P. caused intense hotness and drought in the basin, evaporating the shallow marshes. A slight recovery came afterwards with runoff and marshes being restored before the Late Holocene Dry Period 3,300-2,200 and 2,000-1,800 Y.B.P., which caused extreme drought conditions.[7] After that, the temperature fell and moisture was restored. Two large lakes formed between 1519 and 1308 B.P. and 915 to 652 B.P. with water levels fluctuating between 1,198 m (3,930 ft) and 1,204 m (3950 ft). The Salt Wells beach barrier and surrounding features provides evidence that a substantial lake was present in the Carson Sink <2 ka, a lake that would submerge the late Holocene archaeological sites in the Stillwater Marsh beneath at least 20 m of water.[6] In that time, the Roman and Medieval periods had extreme drought while the Little Ice Age brought 4-5 fold more water in the Carson River.

Pioneers Settling Down in the Basin

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During the California Gold Rush, the sink lay across the route of the Carson Trail, which branched off from the Humboldt Bar. The trail went across the Lahontan Basin, and it included a section through the Forty Mile Desert to the first drinkable water on the Carson River.[8] The Carson Sink station of the Pony Express was built in March 1860, and the Pony Express crossed the basin until 1861.[9]Early settlers in the 1860s attempted to farm barley in the sink but found the crop was too short to harvest. In 1918, the Truckee-Carson Irrigation District brought diverted water from the Truckee River into the region, allowing for increased agriculture in the vicinity of the sink along the Carson River.

Image of Carson Sink in 1910.

Carson Sink UFO Incident

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In June 1952, two U.S. Air Force colonels flew a B-25 bomber from Hamilton Field near San Francisco to Colorado Springs, Colorado. While passing over Carson Sink, the two reportedly saw three unknown aircraft fly within 800 yards (731.5 m) of their aircraft before speeding out of sight seconds later. Upon landing, the two colonels reported the incident to the Air Defense Command headquarters, who informed them that there were no military or civilian aircraft in the area at the time. The incident was never resolved and is known today as the Carson Sink UFO incident.[10]

Modern Flood Events

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1861-1862

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Image of Carson Basin in 1910.

In the Great Flood of 1861-1862, two feet of wet, heavy snow was deposited on the Carson Valley's floor after a storm in December 20, 1861. Following that, very cold temperatures afterwards caused the snow to freeze, then came a 3 day rainstorm from December 25 to 27, 1861. By January 2, 1862, the towns Empire and Dayton were flooded, and drownings were recorded and buildings, bridges, and a stamp mill were swept away.[11] Due to those floods, the Carson river re-occupied an abandoned channel and started flowing directly northward to the southwestern Carson Sink instead of going through Carson Lake. The floods flooded the sink to record levels of 3,890 ft (1,186 m) high, a area of 1,300 sq km, a volume of 5.7 cubic km, and a depth over 15 feet.

1982-1984

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During flooding between 1982 and 1984, both the Humboldt and Carson Rivers emptied enormous amounts of water into the Humboldt Basin and Carson Sink.[12] In 1984, the natural dike between the Carson Sink and the Humboldt Sink was breached by the Nevada Department of Transportation to make the Lower Humboldt Drain to prevent Interstate 80 and the town of Lovelock from flooding due to unusually heavy snowfall and spring rainfall in the preceding three years. This action flooded the Carson Sink.  Excess water flowed from the Humboldt and other drainages into the Carson Sink, the lowest point in northwestern Nevada - below 39,360 feet (1,200 m) in elevation. In 1982, prior to spring runoff, the Stillwater Marsh had stood at an all-time low of 8,500 acres (3,400 ha) of water.  By the summer of 1984, over 220,000 acres (88,000 ha) of the Carson Sink were flooded with a maximum depth of 12 feet.  The vegetation in the marshes died; so did the fish and the birds. Dikes were breached, nesting areas vanished.[12]

Image of Carson Basin in 1979.

In 1985, the Carson Sink's water level extent was 3,881 ft (1,183 m) with an area of 890 sq km (344 sq mi) and a water volume of 5.7 cu km. The sinks remained connected by the Lower Humboldt Drain for two years, until 1986 when the slough became completely dry. The water level in the Carson Sink started retreating to its usual state and by 1988, it was completely dry. In February 1987, at least 7 million Tui Chub died on 30 miles of the Sink's shoreline due to lethal increases in salinity and shrinking of the temporary lake by natural causes and man-made irrigation water diversions. The lake size by then had shrunk to 180,000 ac (72,843 ha) and was only 2 feet deep. Also included was a die-off of 1,500 waterfowl from Avian Cholera.[13] [14]

Panorama

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Carson Sink view
Panorama of the Carson Sink

See also

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References

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  1. Bryce, S.A; et al., Ecoregions of Nevada (PDF) (poster), Reston, Virginia: USGS, retrieved January 12, 2020
  2. Morrison, R. B; Fry, John C (1965). "Correlation of the Middle and Late Quaternary Successions of the Lake Lahontan, Lake Bonneville, Rocky Mountain (Wasatch Range), Southern Great Plains, and Eastern Midwest Areas" (PDF). Nevada Bureau of Mines. Archived from the original (PDF) on June 6, 2010. Retrieved November 24, 2010.
  3. 1 2 3 Fallon Range Training Complex, Naval Strike and Air Warfare Center (NSAWC)
  4. Bengston, Ginny (2003). Northern Paiute and Western Shoshone Land Use in Northern Nevada: A Class I Ethnographic/Ethnohistoric overview (PDF) (Report). Cultural Resource Series. BLM. Archived from the original on March 23, 2022. Retrieved November 1, 2024.{{cite report}}: CS1 maint: bot: original URL status unknown (link)
  5. "Lake Lahontan Expedition". RangeRovers.net. Archived from the original on July 12, 2013. Retrieved July 12, 2013.
  6. 1 2 Rhode, David; et al. (January 1, 2000). "Geoarchaeology and Holocene landscape history of the Carson Desert, western Nevada". GeoScienceWorld. Retrieved June 23, 2026.
  7. Thomas, David; et al. (May 6, 2023). "Great Basin Survivance (USA): Challenges and Windfalls of the Neoglaciation / Late Holocene Dry Period (3100–1800 cal BP)" (PDF). USDA.
  8. "Carson Trail". Trails West.org. Retrieved July 12, 2013.
  9. "Carson Sink". Archived from the original on August 4, 2013. Retrieved July 12, 2013.
  10. Edward Ruppelt (March 1, 2007). The Report on Unidentified Flying Objects. Echo Library. pp. 15–. ISBN 978-1-4068-4084-1. Retrieved October 25, 2011.
  11. "Nevada Flood Chronology". 2013.{{cite web}}: CS1 maint: url-status (link)
  12. 1 2 Baldrica, Alice (1998). [chrome-extension://efaidnbmnnnibpcajpcglclefindmkaj/https://marshall.csu.edu.au/DigiBooks/DisManSFO/21-Baldrica.pdf "Flood Case Study: Stillwater, Nevada"] (PDF).{{cite web}}: CS1 maint: url-status (link)
  13. CHEREB, SANDRA (February 21, 1987). "Death at Stillwater -- an ecological disaster". UPI.{{cite news}}: CS1 maint: url-status (link)
  14. CHEREB, SANDRA (February 19, 1987). "Millions more fish die at refuge".{{cite news}}: CS1 maint: url-status (link)