Basin Republican-Rustler Printing Building

The Big Horn Basin of northwest Wyoming was first seen by the white man as early as 1807 when John Colter, a former member of the Lewis and Clark expedition, was sent into the area by fur trapper and trader, Manuel Lisa. Colter's job was to explore the twin possibilities of trapping beaver and trading with the Crow Indians. Four years later Wilson Price Hunt and his eastward-bound Astorians pierced the southeast fringe of the basin en route to the Pacific Coast, but a thorough exploration of the basin's interior by fur trappers did not occur until about a decade later. The Big Horn River was used to transport furs from the lower canyon to the Yellowstone River, but it was not until the summer of 1825 that William H. Ashley first used the river to move furs the full length of the Big Horn Basin. The first official government expedition to explore the basin was that of 1859-60, commanded by Captain W. F. Raynolds and guided by renowned mountain man and scout, Jim Bridger. Later, in 1864, Bridger led a party of miners from present-day Casper, through the Owl Creek Mountains and the basin to the gold fields of Montana, using an improved trail that became known as the Bridger Road Bridger's Road, however, was not as popular as the Bozeman Road located on the east side of the Big Horn Mountains, even though the latter was made a far more dangerous route by Indians who fought to retain control of the Powder River Basin, an area that was theirs by treaty.

Despite the 1867 rush to the Sweetwater gold mines of the southern Wind River Mountains and the construction of the Union Pacific Railroad across southern Wyoming in 1868, the Big Horn Basin remained isolated to white settlement. North of the basin, Crow Indians were established on a reservation along the Yellowstone, and on the south edge of the basin was the Shoshone reservation. Of this isolation, historian Charles Lindsay wrote:

The Wyoming frontier had thus, by 1869, receded several hundred miles to the south and east. The northeastern quarter of the territory was a virtual reservation. The Platte, the Sweetwater, the upper Popo Agie, and the upper Wind River, represented, for all practical purposes, its exposed line on the north. Reaching the Big Horn Basin from the east, the north, or the south, without trespassing upon Indian treaty grounds, was next to an impossibility.

In 1870 a mining expedition penetrated the basin but met with little success, and in the 1870s and 1880s, there were only spasmodic attempts to mine in the Big Horn Mountains.