Colter’s return route from the area near the outlet of Yellowstone River supplies the final link in the figure eight. To reach the Yep-pe Indian camp he might have veered to the northeast, crossed Yellowstone River at the ford below Mud Volcano, and ascended Pelican Creek or one of the tributaries of the Lamar River. After crossing the Absarokas he evidently descended one of the creeks that empty into Clarks Fork. No one on earth can be certain about this part of his journey. There is no reference anywhere, and the Map of 1814 gives no clue. Still he did reach a tributary of Clarks Fork which he followed to its junction with Dead Indian Creek, thence to the Yep-pe band. BIBLIOGRAPHICAL NOTE In the preparation of the first four chapters the use of explorer and trapper journals was imperative. The _Journals of Lewis and Clark_, Patrick Gass’s _Journal_, and Robert Stuart’s _Discovery of the Oregon Trail_ are basic. Trapper activities and Indian life are effectively treated by Stallo Vinton in _John Colter_; Alexander Ross, _The Fur Hunters of the Far West_; Hiram Chittenden, _The American Fur Trade_; John Neihardt, _The Splendid Wayfaring_; J. Cecil Alter, _Jim Bridger, Trapper, Frontiersman, Scout and Guide_; Bernard De Voto, _Across the Wide Missouri_; and Robert Vaughn, _Then and Now_. A correct conception of original Indian life and character will reward the student of Rudolph Kurz’s _Journal_ and Washington Irving’s two volumes: _The Adventures of Captain Bonneville_ and _Astoria_. George Catlin’s monumental treatise on _North American Indians_ is also a classic on that subject. Important in the field of writings dealing with the partial and final discovery of Yellowstone are Nathaniel P. Langford, _Discovery of Yellowstone Park 1870_, together with the shorter accounts of his companions as recorded in Louis C. Crampton’s _Early History of Yellowstone National Park and Its Relations to National Park Policies_. The Yellowstone explorations of James Stuart and Walter W. DeLacy and others are found in _Contributions to the Historical Society of Montana_, volumes one to five inclusive. John G. White’s scholarly manuscript entitled “A Souvenir of Wyoming” contains much material of a provocative character. Nice points of detail are raised concerning John Colter’s route and other trapper visitations. The chapter on “Travel and Accommodations—New Businesses” was the result of a search through the standard magazines covering the half century from 1870 to 1920. The State College of Washington collection was found adequate for this survey.