Colter, it is therefore assumed, followed the great trail along the Absarokas to the Wind River Valley, and crossed the divide by one of the easy passes at its head. His two crossings of the Teton range were along established trails. He evidently lost his bearings somewhat in the vicinity of the Yellowstone Lake, but as soon as he arrived at the river below the lake he kept along the trail until he reached the important crossing at Tower Falls. If he was in company with Indians who had ever been through that country before, he learned that it would be no advantage to cross at Mud Geyser, inasmuch as he would strike the great Bannock Trail at the next ford below. Moreover, the distance below the lake to the point where Colter touched the Yellowstone is clearly greater than that to the Mud Geyser Ford. The bend in the river at the Great Falls, and the close proximity of the Washburn Range to the river, are distinctly indicated. The locality noted on the map as "Hot Springs Brimstone" is evidently not that near the Mud Geyser, as generally assumed, but instead, that of the now world-renowned Mammoth Hot Springs. As will be seen from the map, it is nearer the Gallatin River than it is to the Yellowstone _where Colter crossed_. If Colter visited the Springs from Tower Falls, as is not unlikely, a clue is supplied to the otherwise perplexing reference to the Gallatin River in the above extract from the _Missouri Gazette_, for it would thus appear that he was near the sources of both the Grosse Corne and of the Gallatin. The essential difficulties in the way of this theory (and they exist with any possible theory that can be advanced) are the following: (1.) There is no stream on the map that can stand for the Snake River either above or below Jackson Lake, although Colter must have crossed it in each place. "Colter's River" comes nearest the first location, and may possibly be intended to represent that stream; but Clark's evident purpose to drain Jackson Lake into the Bighorn River doubtless led to a distortion of the map in this locality. (2.) The erroneous shape given to the Yellowstone Lake will be readily understood by any one who has visited its western shore. The jutting promontories to the eastward entirely conceal from view the great body of the lake and give it a form not unlike that upon Clark's map. (3.) The absence of the Great Falls from the map is not easily accounted for, although the location and trend of the Grand Cañon are shown with remarkable accuracy. (4.) The absence of the many hot springs districts, through which Colter passed, particularly that at the west end of the Yellowstone Lake, may be explained by the same spirit of incredulity which led to the rejection of all similar accounts for a period of more than sixty years. It is probable that Clark was not willing to recognize Colter's statements on this subject further than to note on his map the location of the most wonderful of the hot springs groups mentioned by him.