Although only a short span of time in the history of the Black Hills, the decades between 1851 and 1877 were momentous ones.
By the 1860s, only a few areas in the Plains, including the Republican Fork and the Tongue/Powder river countries, held bison herds large enough to sustain a livelihood for the Lakotas, Cheyen.
This was a time when bison began to disappear from the Black Hills and the surrounding prairies, forcing local tribes to move even farther away to find good bison hunting grounds.
Although only a short span of time in the history of the Black Hills, the decades between 1851 and 1877 were momentous ones