Plan of Okanogan River and Osoyoos Lake, Similkameen River to international boundary, Washington; topography by Gordon C. Giles, H. L. Pumphrey, and Arthur Johnson, surveyed in 1944 and 1945. Scale 1:4,800 or 1 in.=400 ft., contour interval 2 and 5 ft., changing at 920 contour. n. p.