By that time they would be well into the prodigious mountainous region which would confront them for a thousand miles or more, for it is the foothills of the Rockies. The present state of Colorado is traversed by the main axis or continental divide of the Rocky Mountains which there finds its greatest northern development. The culminating crest of the main range is the Wind River Mountains in the west-central part of the State, which is traversed by numerous other ranges, including the Big Horn in the north-central section, the Laramie Mountains already mentioned, the Medicine Bow in the south; north of them the Sweetwater and Rattlesnake ranges, and in the west the Teton, Shoshone and Gros Ventres mountains. The extreme northeast is penetrated by the Black Hills from South Dakota. The loftiest peak is Fremont’s in the Wind River Mountains, two and a half miles high, with others of almost as great elevation.