The Lahontan Valley is in Churchill County in the U.S. state of Nevada. The valley is a landform of the central portion of the prehistoric Lake Lahontan's lakebed of 20,000-9,000 years ago. The valley and the adjacent Carson Sink represent a small portion of the lake bed, and Humboldt Lake is to the valley's northeast (Pyramid Lake is west and Walker Lake is south). Aside from the city of Fallon, the railroad junction at Hazen, and the ghost town of Stillwater, the Lahontan Valley is mostly uninhabited desert. During the era of the California trail the Lahontan and adjacent valleys to the northwest were called the Forty Mile Desert.