eter Pond, an American but one employed by the Northwest Company, a fur trading enterprise with headquarters in Montreal, presented the United States Congress with a map in 1784. This instrument, based on Pond's travels in the West, adhered to the erroneous French theory about a single range of mountains that did much to mislead a generation or two of armchair and practical geographers about the true complexity of the Rocky Mountain system.

Faithful to the reigning theory, Pond's map showed a westward flowing river emanating from a narrow ridge opposite to the headwaters of the Missouri. Remarkably enough, Pond speculatively placed the common wellspring of these great rivers at the 45th parallel -- precisely the latitude of what would later be named Lemhi Pass. (Nicandri:2005)

Have fun exploring the details of the map below by taking advantage of the DjVu map viewer to see high resolution maps online.