1842 On August 1, 1842, the "exploring expedition to the Rocky Mountains" led by Brevet Capt. John C. Fremont reached Rock Independence. Fremont wrote "This is an isolated granite rock, about six hundred and fifty yards long, and forty in height. Except in a depression of the summit, where a little soil supports a scanty growth of shrubs, with a solitary dwarf pine, it is entirely bare. Everywhere within six or eight feet of the ground, where the surface is sufficiently smooth, and in some places sixty or eighty feet above, the rock is inscribed with the names of travelers. Many a name famous in the history of this country, and some well known to science are to be found mixed among those of the traders and of travelers for pleasure and curiosity...."
1843 John C. Fremont arrived at the Medicine Bow Mountains and encamped on the Medicine Bow River. He then moved toward the North Platte River, up the Sweetwater Valley to South Pass, where in his report he says he met on August 4th "a war party of Arapaho and Cheyenne Indians, who had surprised one of the Shoshone villages at Bridger's Fort on Ham's fork on Green River." From the South Pass he followed "the emigrant road to Oregon," until he struck Green River, where he dispatched Kit Carson to Fort Hall to make arrangements for a supply of provisions. From the Green River to the Bear River, he followed the route taken by Ezekiel Williams in1807 until he arrived at Salt Lake. (History of Wyoming Bartlett)
1915 On August 1, 1915, "generally traveled roads in Yellowstone National Park were opened to motor driven vehicles, operated for pleasure purposes only, under strict regulations." (Annual Report, Interior, 1915)