Research materials (photographs copied from originals in other institutions, notes, letters, printed pamphlets) and manuscripts from Dunlop's books on the American West, mainly Wheels West. Also materials from Chicago Corral of Westerners, of which Dunlop was a long-time member. Dunlop, a native Chicagoan and history graduate of Northwestern University, also wrote the Rand McNally Backpacking and Outdoor Guide, Doctors of the American Frontier, and Great Trails of the West.