Crab Creek flows 163 miles through central Washington's Columbia Basin, beginning near Reardan in Lincoln County and flowing west-southwest through Grant County before emptying into the Columbia River near Beverly. Named for the presence of crayfish, this is one of the few perennial streams in the Columbia Basin, though upper sections remain intermittent. The creek's course showcases dramatic evidence of the ancient Missoula Floods, with erosive features carved through the channeled scablands and basalt flows. Flowing through an elevation drop from 2,730 feet at its source to 489 feet at the mouth, Crab Creek passes through or connects several lakes including Sylvan Lake, Brook Lake, Moses Lake, and Potholes Reservoir. Average discharge measures 201 cubic feet per second, ranging from 10 cfs during low flows to 936 cfs at peak. The lower reach near Lenice and Nunnally lakes has gained particular fame among fly anglers as a destination fishery, while other sections support diverse warmwater and coldwater opportunities.