The Lahontan Trough refers to the remnants of Lake Lahontan, a large Pleistocene lake that once covered much of present-day Nevada. The trough contains significant lacustrine deposits that provide insights into the climatic and hydrological history of the Great Basin during the Ice Age.
Source Benson, L. V., & Thompson, R. S. (1987). “Lake-Level Variation in the Lahontan Basin for the Past 50,000 Years.” Quaternary Research, 28(1), 69-85.