The Carson River is a northwestern Nevada river that empties into the Carson Sink, an endorheic basin. The main stem of the river is 131 miles (211 km) long although the addition of the East Fork makes the total length 205 miles (330 km), traversing five counties: Alpine County in California and Douglas, Storey, Lyon, and Churchill Counties in Nevada, as well as the Consolidated Municipality of Carson City, Nevada. The river is named for Kit Carson, who guided John C. Frémont's expedition westward up the Carson Valley and across Carson Pass in winter, 1844. The river made the National Priorities List (NPL) on October 30, 1990 as the Carson River Mercury Superfund site (CRMS) due to investigations that showed trace amounts of mercury in the wildlife and watershed sediments.

Carson Sink is a playa 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. Today the sink is 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.