Black River Falls, Wisconsin, United States [City]; population was 3,490 in 1990; housing units was 1,547 in 1990; location is 44°18'N 90°51'W; land area is 2.94 square miles (1,880 acres); water area is 0.10 square miles (62 acres); FIPS code is 7900 [SourceCBP]