He [Lisa] continued his voyage to the Yellowstone River, where he built a trading fort. He shortly after dispatched Coulter, the hunter before mentioned, to bring some of the Indian nations to trade. This man, with a pack of thirty pounds weight, his gun and some ammunition, went upwards of five hundred miles to the Crow nation; gave them information, and proceeded from them to several other tribes. On his return, a party of Indians in whose company he happened to be was attacked, and he was lamed by a severe wound in the leg; notwithstanding which, he returned to the establishment, entirely alone and without assistance, several hundred miles. Aside from this slim clue, his course can be determined solely on the basis of “Colter’s Route in 1807” and other data which appear on William Clark’s “Map of the West,” published in 1814, presumably based on a conversation of 1810 at St. Louis, whither the trapper-explorer returned after hair-raising adventures with the Blackfeet in the Three Forks country. Inevitably, in view of the topographical errors and distortions of the Clark map, Colter’s precise route is subject to wide differences of opinion. A composite of theories offered by Hiram M. Chittenden, Stallo Vinton, Charles Lindsay, and Burton Harris, to mention only four qualified scholars who have undertaken to hypothecate Colter’s route, is that Colter ascended the Bighorn, followed up the Shoshone River to near present Cody, went south along the foot of the Absaroka Mountains, up Wind River to Union Pass, into Jackson’s Hole, thence probably across Teton Pass into Pierre’s Hole, thence north via Conant Pass to the west shore of Yellowstone Lake and northeast to the crossing of the Yellowstone near Tower Falls, thence up the Lamar River and Soda Butte Creek, back across the Absarokas, thence south to the Shoshone River, and back to Lisa’s Fort by way of Clark’s Fork and Pryor’s Fork. The key to Colter’s route is the identification of Lakes Jackson and Yellowstone, respectively, as Clark’s Lake Biddle (named for the patron of his publication) and Lake Eustis (named for the Secretary of War), no longer questioned by historians. The “Hot Spring Brimstone” at the sulphur beds crossing of the Yellowstone River near Tower Falls and the “Boiling Spring” near the forks of the Stinkingwater or Shoshone (see Chapter IV) are other checkpoints which now seem quite firm. In addition, there are two interesting claims of physical evidence. While these are both necessarily debatable and subject to challenge as hoaxes, they deserve consideration. According to Philip A. Rollins, quoted by Vinton: