The Black Hills is an isolated mountain range rising from the Great Plains of North America in western South Dakota and extending into Wyoming, United States. Black Elk Peak, which rises to , is the range's highest summit. The Black Hills encompass the Black Hills National Forest. The name of the hills in Lakota is Pahá Sápa. The Black Hills are considered a holy site. The hills are so called because of their dark appearance from a distance, as they are covered in evergreen trees.
Native Americans have a long history in the Black Hills and consider it a sacred site. After conquering the Cheyenne in 1776, the Lakota took the territory of the Black Hills, which became central to their culture. In 1868, the U.S. government signed the Fort Laramie Treaty of 1868, establishing the Great Sioux Reservation west of the Missouri River, and exempting the Black Hills from all white settlement forever. However, when settlers discovered gold there in 1874, as a result of George Armstrong Custer's Black Hills Expedition, miners swept into the area in a gold rush. The US government took the Black Hills and forcibly relocated the Lakota, following the Great Sioux War of 1876, to five smaller reservations in western South Dakota, selling off of their former land. Unlike most of South Dakota, the Black Hills were settled by European Americans primarily from population centers to the west and south of the region, as miners flocked there from earlier gold boom locations in Colorado and Montana.
As the economy of the Black Hills has shifted away from natural resources (mining and timber) since the late 20th century, the hospitality and tourism industries have grown to take its place. Locals tend to divide the Black Hills into two areas: "The Southern Hills" and "The Northern Hills." The Southern Hills is home to Mount Rushmore, Wind Cave National Park, Jewel Cave National Monument, Black Elk Peak (the highest point in the United States east of the Rockies, Custer State Park (the largest state park in South Dakota), the Crazy Horse Memorial, and The Mammoth Site in Hot Springs, the world's largest mammoth research facility.