Lewis and Clark -- U.S. County in Montana Population (2000): 55716 Housing Units (2000): 25672 Land area (2000): 3460.959273 sq. miles (8963.842986 sq. km) Water area (2000): 36.601206 sq. miles (94.796685 sq. km) Total area (2000): 3497.560479 sq. miles (9058.639671 sq. km) Located within: Montana (MT), FIPS 30 Location: 46.813873 N, 112.153933 W Headwords: Lewis and Clark Lewis and Clark, MT Lewis and Clark County Lewis and Clark County, MT