Deposit

Searles Lake

Searles Lake is a deposit with published resource estimates in California, recorded in the USGS lithium deposits in the United States selected-sites dataset (2020 release).

Facts on this page last re-verified Aug 18, 2026 — the oldest verification date among its current claims. How we verify.

Location: California, United States (35.717, -117.327 approx.)

Commodities: lithium; tungsten; salt; borax

Deposit model: evaporites · lithium brine · unclassified

Geology

"Searles Lake is underlain by 693 m of saline mineral layers that alternate with layers of mud and clay. Below this level to a depth of 915 m is arkose, deposited as an alluvial fan by intermittent streams. Quartz monzonite bedrock underlies the arkose. The saline minerals were deposited during dry periods when the lake shrank to a low level or to dryness. Mud and clay were deposited in a deep perennial lake during pluvial times. The saline layers contain an uncommon variety of saline mineral species. The chemical composition of the brine and the minerals in each saline layer depended on the chemical composition of the inflowing water at that time and on climatic factors such as temperature, precipitation, and evaporation." (Cowie (1985))

Published resource estimates

As compiled by USGS USMIN from the cited studies. Resource classes follow the source; "approximate" flags values USMIN reports as approximations. These are not current company reserve statements.

Material	Class	Amount	Grade	Contained	As of	Reference
lithium (Li)	Subeconomic	—	—	—	Jan 1, 1960	Anstett and others (1990), Page 25, Table 12 — Anstett, T.F., Krauss, U.H., Ober, J.A., and Schmidt, H.W., 1990, International Strategic Minerals Inventory Summary Report – Lithium: U.S. Geological Survey Circular 930-1, 28 p. [Also available at . https://doi.org/10.3133/cir930I]
tungsten trioxide (WO3)	Unclassified	—	70 parts per million	—	Jan 1, 1959	Carpenter and Garrett (1959), Page 301 — Carpenter, L.G., and Garrett, D.E., 1959, Tungsten in Searles Lake: Mining Engineering, v. 11, no. 3, p. 301-303.
lithium (Li)	Probable	—	0.005 percent	—	Jan 1, 1976	Kesler (1978), Page 284, Table 3 — Kesler, T.L., 1978, Raw Lithium Supplies: Transactions of the American Institute of Mining, Metallurgical and Petroleum engineers, Incorporated, v. 264, p. 283-284.

Recorded production

Searles Lake, Searles Lake mine: produced an unstated amount of dilithium sodium phosphate (Li2NaPO4) at 10.111 percent, containing about 16.1 metric tons Li, 1938–1976 (Garrett (2004), Page 133)

Exploration and site history

Active — Intermittent mining of Searles Lake, 1873–2018 (Searles Valley Minerals (2018))
Active — The recovery of lithium concentrates commenced in 1936, 1936–1979 (Mohr and others (2010); Rykken (1976))
Discovery — Tungsten was first recognized in the Searles Lake brine, 1937 (Carpenter and Garrett (1959))
Discovery — Borax discovered, 1862 (Searles Valley Minerals (2018))
Discovery — Trona was discovered in 1905, 1905 (Searles Valley Minerals (2018))

Record imported from USGS USMIN ver. 4.0 (June 2019). Developments after that date appear on facility records, not here; see the methodology.

Sources

U.S. Geological Survey · published Jun 1, 2020 · retrieved Aug 18, 2026 · archive