Humboldt Sink, Dry lake basin in Pershing County, Nevada, US.

Humboldt Sink is an intermittent dry lake bed about 11 miles long and 4 miles across in northwestern Nevada, between the West Humboldt Range and the Trinity Range. Its flat, pale tan and off-white floor has darker streaked patches and is bordered by low brown-grey hills and a rough foreground slope. The Humboldt River feeds it from the northeast.

The sink and its surroundings formed the Forty Mile Desert, a feared stretch of the overland California Trail during the mid-1800s migrations. It is a remnant of prehistoric Lake Lahontan, which existed about 13,000 years ago at the end of the last ice age. In 1984 the Nevada Department of Transportation cut a channel linking it to the Carson Sink to protect I-80 and Lovelock from flooding; the channel has been dry since 1986. It takes its name from the Humboldt River, named for German naturalist Alexander von Humboldt.

Native peoples inhabited this region for thousands of years, using the waters and surrounding land for hunting and gathering. Evidence of their presence remains in archaeological sites nearby, revealing how communities adapted to life in this arid landscape.

Interstate 80 runs along the northwest side of the sink, between the Trinity Range and the flat basin floor. The bed itself is a broad, pale tan expanse of smooth silt with darker streaked patches, bordered by low brown and grey hills. There is no trail or facility; access is over open desert terrain, and the surface is best crossed on foot or by vehicle in dry conditions.

The basin has no natural outlet, so water from the Humboldt River ends here and simply evaporates. This trapped-water situation creates salt concentrations that shift with the seasons and over time.