Lake Walcott is a reservoir in south central Idaho in the northwestern United States, impounded by Minidoka Dam. The damming of the Snake River by the Minidoka Project formed the 11,000 acre (45 km²) lake beginning in 1909. "Bird Island" is an island in the lake. Lake Walcott is used for water-sports and fishing; although swimming in the lake is currently not allowed. The Minidoka National Wildlife Refuge adjoins the lake is a major attraction in the region.