Lot of three U.S. Railroad Surveys maps. Set includes: 1) "Sketch of the progress of the Northern Pacific Rail Road Exploration up to the crossing of the Shayen River" by Isaac Stevens, 1853 (25 x 15.5"). Includes a lower route from White Bear Lake to Shayen, the Red River Trail. 2) "Sketch of Capt. Gunnison's Route to Central Pacific Rail Road Exploration Sept. 20th 1853" (20.5 x 13"). Indians killed Gunnison before he completed this survey. It is a great early map of present-day Colorado. It details several exploratory routes in the Rocky Mountains. 3) "Sketch of the Northern Pacific Rail Road Exploration from St. Paul to Fort Union" by Isaac Stevens, 1853 (32 x 17"). This map shows Stevens' route and the route of Lt. Grover from Pike Lake to Ft. Union. Wheat notes that these three maps are earlier versions of the maps contained in the quarto version of the Pacific Railroad Surveys and Explorations.

References: Wheat (TMW) #861 & 842.

Condition: B

All in near very good condition with toning along some folds. Issued folding, now pressed and backed with archival tissue.