Includes routes of explorers and surveyors; railroad surveys; military expeditions, including dates.Originally compiled under the direction of Capt. D.P. Heap...by W.H. Wood, 1872.each sheet approximately 49 x 90 centimetersJPEGUMN_ALMA:9921045830001701engCorps of EngineersPublicDakota TerritoryMapsNorth DakotaSouth Dakota1881University of Minnesota