Found some more in the Black Hills page. No mention of bounty hunters.

European Americans increasingly encroached on Lakota territory. In order to secure safe passage of settlers on the Oregon Trail, and to end intertribal warfare, the United States government proposed the Fort Laramie Treaty of 1868, which established the Great Sioux Reservation west of the Missouri River and acknowledged indigenous control of the Black Hills. The treaty protected the Black Hills “forever” from European-American settlement. Both the Sioux and Cheyenne also claimed rights to the land, saying that their cultures considered it the axis mundi, or sacred center of the world.

During the 1875–1878 gold rush thousands of miners went to the Black Hills; in 1880, the area was the most densely populated part of the Dakota Territory.

The conflict over control of the region sparked the Black Hills War (1876), also known as the Great Sioux War, the last major Indian War on the Great Plains. Following the defeat of the Lakota and their Cheyenne and Arapaho allies in 1876, the United States took control of the Black Hills. Despite their forced relocations, the Lakota never accepted the validity of the US appropriation. They have continued to try to reclaim the property, and filed a suit against the federal government.

On July 23, 1980, in United States v. Sioux Nation of Indians, the Supreme Court of the United States ruled that the Black Hills were illegally taken by the federal government and ordered remuneration of the initial offering price plus interest, nearly $106 million. The Lakota refused the settlement, as they wanted the Black Hills returned to them. The money remains in an interest-bearing account, which, as of 2015, amounts to over $1.2 billion, but the Lakota still refuse to take the money. They believe that accepting the settlement would allow the US government to justify taking ownership of the Black Hills.[citation needed]