The Black Hills Gold Rush began in the 1870s when gold was discovered in the Black Hills of present-day South Dakota. This area, sacred to the Lakota Sioux, attracted thousands of prospectors seeking fortune. The rush led to the establishment of towns like Deadwood and Lead, which quickly grew as miners flocked to the region. The discovery of gold in the Black Hills intensified tensions between the U.S. government and the Lakota Sioux, who had been promised the land in the Treaty of Fort Laramie (1868). The rush ultimately contributed to conflicts, including the Black Hills War, as settlers encroached on Native American territories.