Maps. Plan, Swan River, mile 2 to Swan Lake, Mont., dam site, topography by Arthur Johnson, W. L. Thomas, and G. C. Giles, horizontal control in part by Corps of Engineers, Army, surveyed in 1943 and 1944. Scale 1:31,680, scale 2 in.=1 m., contour interval on land 10 ft., on river surface 5 ft. n. p.