Your questions are perfectly logical = and are the=20 result of my failure to be more precise. I think the river that = Colter=20 forded in the northern part of present-day Yellowstone Park was the = Lamar, not=20 the Yellowstone--just east of Tower Falls. North of the Lamar and = upstream=20 a little ways there were several sizeable hot springs just = southeast of=20 Druid Peak (presently much less active since the Madison Quake in = 1959). I=20 think that these thermal phenomena are those Clark noted on his map. I = also=20 think that Clark made an error in transcribing Colter's data that was = probably=20 delivered verbally rather than in map form since there is no evidence = that=20 Colter ever drew a map. If Colter had gone west of Yellowstone Lake, it = would=20 have been difficult for him to miss the Heart Lake geyser basin, the = West Thumb=20 geyser basin, the Dragon's Mouth and Sulfur Springs near the outlet of = the=20 Yellowstone River (you can both hear and smell those from a mile or more = away),=20 or the Yellowstone's Grand Canyon--none of which Clark inserted on his = map. The=20 Bannock Trail that Colter probably followed out of the Park crossed the=20 Yellowstone from the west near Tower Falls but above the junction = of the=20 Lamar and Yellowstone and then crossed the Lamar near the thermal region = that=20 Clark notes on his map. This is probably where Colter joined with the = Bannocks=20 and traveled east with them. Of course it is possible that Clark's = map is=20 an accurate rendering of Colter's route and Colter did, in fact, go west = of=20 Yellowstone Lake--but I doubt it because of so much missing data that = Clark=20 would surely have entered if Colter had seen it and told him about = it. Why=20 show the Shoshone Canyon and Clark's Fork Canyon on the map (as Clark = did) and=20 not the Grand Canyon of the Yellowstone and the two huge = falls which would=20 have been pretty hard for Colter to miss if he followed the Yellowstone=20 downstream from the Lake? Of course, we'll never know but that's part of = the fun=20 of attempting to fit Clark's cartography into what makes sense as we = look at=20 modern maps. And maybe I'll change my mind as I continue to study=20 this.

Finally, there are two important things = to keep in=20 mind. First, Billy Clark is one of my heroes but I'd be the first = to admit=20 that his post-expedition mapping still left a lot of unanswered = questions and=20 got a lot of the geography that he himself hadn't seen just plain dead = wrong.=20 Consider that in an area about 100 miles square he shows the headwaters = of the=20 Yellowstone, Big Horn, Platte, Arkansas, Rio Grande, and Snake! And = second,=20 we also can't forget the possibility = of Colter=20 himself being wrong about just where he went. Imagine a guy just = out of the=20 mountains after nearly 5 years away from what passed for = civilization in=20 St. Louis heading first for a tavern and then to see Cap'n Clark to = report on=20 his travels--might have been more than one or two errors in the process = data=20 transmission!