The reservation was created by treaty in 1855, which defined its boundaries as follows: Commencing in the middle of the channel of the Deschutes River opposite the eastern termination of a range of high lands usually known as the Mutton Mountains; thence westerly to the summit of said range, along the divide to its connection with the Cascade Mountains; thence to the summit of said mountains; thence southerly to Mount Jefferson; thence down the main branch of Deschutes River; heading in this peak, to its junction with Deschutes River; and thence down the middle of the channel of said river to the place of beginning.The Warm Springs and Wasco bands gave up ownership rights to a 10,000,000-acre (40,000 km2) area, which they had inhabited for over 10,000 years, in exchange for basic health care, education, and other forms of assistance as outlined by the Treaty with the Tribes of Middle Oregon (June 25, 1855).

Other provisions of the Treaty of 1855 ensured that tribal members retained hunting and fishing rights in the "Natural and Accustomed Area" which they had vacated.

The Warms Spring people objected and, in 1887, a surveyor named John A. McQuinn determined that they were correct; Handley had incorrectly measured the reservation's boundaries.

The Warm Springs Reservation is one of the last holdouts in the U.S. of speakers of the Chinook Jargon because of its utility as an intertribal language.

Kiksht, Numu and Ichishkiin Snwit languages are taught in the Warm Springs Reservation schools.

The biggest source of revenue for the tribes is hydroelectric (Warm Springs Power Enterprises) projects on the Deschutes River.

Many tribal members engage in ceremonial, subsistence, and commercial fisheries in the Columbia River for salmon, steelhead, and sturgeon.

Tribal members also fish for salmon and steelhead for subsistence purposes in the Deschutes River, primarily at Sherars Falls.

The tribe's fishing rights are protected by treaty and re-affirmed by court cases such as Sohappy v. Smith and United States v. Oregon.

The cannabis project was approved by a vote of tribal members but as of October 2016 still faced administrative and funding challenges.

[12] The two-year-old male wolf had left his White River pack and became the 16th documented gray wolf in the repopulation of wolves in California when he reached Mono County, east of Yosemite National Park in the central Sierra Nevada in February 2021[13] Two adult wolves were found on the reservation in December 2021 by the biologists and two pups were caught on a trail camera in August 2022.