This is a collection of 24 photographs with descriptions showing the terrain along the North Fork of the Koyukuk River north of Wiseman, Alaska. The file includes two maps of the Koyukuk and Hammond River drainages by Robert Marshall and others.

Marshall was in the region during the summers of 1929, 1930, and 1931 and the winter of 1930-31, studying tree-growth at its northernmost limit and mapping the area. For an account and additional information, see his "Reconnaissance of the Northern Koyukuk Valley, Alaska," in MINERAL RESOURCES OF ALASKA, 1931, pp. 247-256. (U.S. Geological Survey BULLETIN No. 844-E located at QE75 .B9 844-E, in the Historical Collections).