This region and much of western America was mapped under adversity, as territory held by hostile Indians. With the dual aims of compiling scientific data and opening the way for settlers, U.S. Army topographers covered ground earlier traversed by conquistadors and mountain men. Earlier travelers mentioned their experiences. The topographers mapped the terrain. The United States Army Topographical Corps from 1838 to 1863 consisted of 36 officers. Barometer, compass, sextant, and pencil were their instruments for handling data on climate, geographical features, soil, feasible routes for wagons or railroads, and sites for towns and industrial developments. Three topographical parties investigated the land that is now Potter County: Lt. James W. Abert invaded this Indian region in 1845 to survey environs of the Canadian and other rivers; Lt. James H. Simpson in 1849 reconnoitered a proposed railroad route from Fort Smith to Santa Fe; Lt. Amiel W. Whipple in 1853 mapped another railroad route from the Mississippi to the Pacific. The United States owes great honor to these and other topographers. (1973)