"Map of a Reconnaissance for a Military Road from the Dalles of the Columbia River to Great Salt Lake under the command of Capt. H.D. Wallen. 4th Inf. By Lieut. Joseph Dixon, T. Engrs.", U.S. War Department
Detailed map of the region between Mt. Hood and the Great Salt Lake. It illustrated Capt. H. D. Wallen's Wagon Road Expedition and shows the Snake River drainage in detail. Forts Wallah Wallah, Dalles, Boise and Hall are shown along with wagon roads and proposed routes. Locates many geographical features, and shows L. Scholl's route of the same year. Excellent topographical and watershed detail.