Topographical map of the road from Missouri to Oregon : commencing at the mouth of the Kansas in the Missouri River and ending at the mouth of the Wallah Wallah in the Columbia [Sheet 1]., map, 1846; (https://texashistory.unt.edu/ark:/67531/metapth192377/m1/1/: accessed April 26, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu; .