The Yakama people were the first known inhabitants of the Yakima Valley. In 1805, the Lewis and Clark Expedition came to the area and discovered abundant wildlife and rich soil, prompting the settlement of homesteaders. A Catholic Mission was established in Ahtanum, southwest of present-day Yakima, in 1847. The arrival of settlers and their conflicts with the natives resulted in the Yakima War. The U.S. Army established Fort Simcoe in 1856 near present-day White Swan as a response to the uprising. The Yakamas were defeated and forced to relocate to the Yakama Indian Reservation.