Question: Warm Springs, Montana has a hospital founded by the territorial government that existed beginning in what year?

Context paragraphs:
Warm Springs Bay: Warm Springs Bay is a 2.4 mile-long bay located just outside the small community of Baranof Warm Springs on Baranof Island in the Alexander Archipelago, Alaska.  Warm Springs Bay receives the outflow of Baranof Lake and Baranof River.  Warm Springs Bay is located at .

Jefferson Pools: The Jefferson Pools, also called Warm Springs Bathhouses and Warm Springs Pools, are two spa structures near Warm Springs, Virginia.  The name was changed in the 20th century from "Warm Spring Pools" to "Jefferson Pools".  The spa is part of The Homestead, a resort hotel.

Warm Spring Run: Warm Spring Run is an 11.9 mi non-navigable tributary stream of the Potomac River in Morgan County of West Virginia's Eastern Panhandle.  It rises on the eastern side of Warm Springs Ridge (1,115 feet) and parallels U.S. Route 522 for most of its course.  Warm Spring Run enters the Potomac River at Hancock.  Warm Spring Run is primarily fed by springs on Warm Springs Ridge, the most well-known of these being the springs at Berkeley Springs State Park in Berkeley Springs through which it flows.

Montana Territory: The Territory of Montana was an organized incorporated territory of the United States that existed from May 26, 1864, until November 8, 1889, when it was admitted as the 41st state in the Union as the State of Montana.

Warm Springs Historic District: Warm Springs Historic District is a historic district in Warm Springs, Georgia.  It includes Franklin Delano Roosevelt's Little White House and the Roosevelt Warm Springs Institute for Rehabilitation, where Roosevelt indulged in its warm springs.  Other buildings in the district tend to range from the 1920s and 1930s.  Much of the district looks the same as it did when Roosevelt frequented the area.

Warm Springs, Arkansas: Warm Springs is an unincorporated community in Randolph County, Arkansas, United States.  Warm Springs is located on Arkansas Highway 251 15.5 mi north-northwest of Pocahontas.  Warm Springs has a post office with ZIP code 72478.

Warm Springs Natural Area: The Warm Springs Natural Area, also known as the Warm Springs Ranch, is located near the Moapa Indian Reservation in Clark County, Nevada, at an elevation of 2123 ft .  The 1179 acre area is owned by the Southern Nevada Water Authority (SNWA).  The area is a natural oasis in the Mojave Desert.  The oasis is fed by close to 24 natural warm springs and contains many naturally occurring California fan palms ("Washingtonia filifera"), creating an ecosystem normally limited to the "low" Colorado Desert and so unique to the "high" Mojave Desert.  The springs are the headwaters for the Muddy River.

Warm Springs, Montana: Warm Springs is an unincorporated community in Deer Lodge County, Montana, United States, operated by the state of Montana.  It is the site of Montana State Hospital, the only long term psychiatric hospital operated by the state of Montana.  The hospital was founded by the Territorial Government of Montana in 1877.  The "warm springs" are located on the hospital campus.  Hot water seeps from a limestone cone that is about 40 feet high.  The Native Americans called this the "Lodge of the Whitetailed Deer" giving the Deer Lodge Valley its name.  There are no community services other than a bar and convenience store on the frontage road and a post office (zip code 59756) on the hospital campus.  Brown trout fishing can be found in the Clark Fork River just east of Warm Springs and in the ponds on the Warm Springs Wildlife Management Area.

Warm Springs (film): Warm Springs is a 2005 television film about U.S. President Franklin D. Roosevelt's 1921 illness, diagnosed at the time as polio, his struggle to overcome paralysis, his discovery of the Warm Springs resort, his work to turn it into a center for the rehabilitation of polio victims, and his resumption of his political career.  Roosevelt's emotional growth as he interacts with other disabled people at Warm Springs prepares him for the challenges he will face as President during the Great Depression.

Warm Springs, Oregon: Warm Springs is a census-designated place (CDP) and an unincorporated community in Jefferson County, Oregon, United States.  Located on the Warm Springs Indian Reservation, the community is also known as the "Warm Springs Agency."  The population was 2,431 at the 2000 census.

Supporting paragraphs: Warm Springs, Montana Montana Territory
Answer: 1864