On June 1, 1873, a camp of Nakoda people were attacked by American wolf hunters near the trading posts of Abel Farwell and Moses Solomon, on what is now the Cypress Hills Massacre National Historic Site. Many Nakoda people were killed, and others suffered further cruelty after the shooting stopped. This event greatly impacted the Nakoda people, and the event would hurry the formation of the North West Mounted Police.

The idea of a dominion police force to patrol the enormous landscape of western Canada was one that the federal government was already pursuing. When news of the massacre reached Ottawa, it supported the fears held by the government with respect to a “lawless” west, and led to the Great March West, which saw the North West Mounted Police arrive in what is now Saskatchewan and Alberta.

Approximately 300 recruits assembled at Fort Dufferin, Manitoba, and on July 8, 1874, set out as six divisions to march west some fifteen hundred kilometers, setting up police posts along the way. The journey was one of great difficulty. The primary goal of the North West Mounted Police at that time was to establish a government presence in the West and to implement Canadian law. Some of their first tasks were to end the illegal whiskey trade and patrol the Canada-United States border. Their route was long, and their trip poorly planned. It came close to failure, but the police force did arrive in the West, and established posts that established government authority. Some of the first settlements in the North West Territory grew around these police posts. The early work of the North West Mounted Police would shape relationships between the Crown and Indigenous peoples, and between Indigenous and non-Indigenous people.

Inspector James Morrow Walsh, and officers from “B” Division of the North West Mounted Police established Fort Walsh in June of 1875. The North West Mounted Police had a wide range of tasks to carry out. The Mounties at Fort Walsh, and elsewhere, were responsible for Customs and Excise. They would also do the work of Quarantine and Brand Inspectors as herds of horses and cattle were brought into the country. Their wagons delivered the mail. The first veterinarian in the west was a Mountie. The only doctors were police surgeons. Officers were magistrates and justices of the peace. They could marry and bury people. They arrested, prosecuted and sat in judgement of offenders. They were law and order, and infrastructure. They were the system as it existed at the time. They were policemen in peacetime, but if war came, they would be infantry, cavalry and artillery. They were representatives of the new Dominion government, and advisors to that government. They were the government, but they were also its servants. And when their terms of service ended, they were among the first settlers and businessmen in the west.

Treaty money was paid at Fort Walsh, and for a few years, government-operated agricultural instruction farms for some bands were established near Fort Walsh. Adhesions to Treaty Four, the process of adding groups of people to the agreements outlined in treaties, were signed at Fort Walsh in 1877 (Man Who Took The Coat, Long Lodge, and Lean Man), and to Treaty Six in 1879 (Lucky Man and Little Pine) and 1882 (Big Bear).

Events in American history such as the Great Sioux War of 1876-1877, and, more specifically, the Battle of the Little Big Horn, also known as Custer’s Last Stand, led to the Lakota crisis. Inspector Walsh and his men at Fort Walsh became closely involved in what was seen as an international incident.

The Wood Mountain area in Canada saw a sudden increase in residents in late 1876 and early 1877. Approximately 5,000 Lakota people left the United States to seek peace and safety in Canada after the Battle of the Little Big Horn, in which they had been attacked by Colonel George Armstrong Custer and his 7th United States Cavalry. The Lakota and their allies defeated Custer and almost wiped out his regiment. The Lakota people came north under the leadership of men like Lame Brule, Spotted Eagle, Bear's Cap, Four Horns, and medicine man and leader Sitting Bull.

Some months later in 1877, General Terry of the U.S. Army led a delegation, known as the Terry Commission, to Fort Walsh. There he met with Sitting Bull and others, encouraging the Lakota people to return back to the United States. It did not work. The Lakota saw no benefit to leaving given the terms of the Terry Commission, and NWMP Commissioner MacLeod saw no reason to force the removal of the Lakota from Canada so long as they stayed peaceful.

Fort Walsh was the Mounted Police post nearest to Wood Mountain. In response to government concerns about the Lakota presence in Canada, the Fort was made Headquarters of the police force in 1878, receiving more resources and an increased number of men. To monitor the Lakota presence, Fort Walsh would remain headquarters until 1882. Lack of food and resources would drive most of the Lakota people to return to the United States, where they would have to comply with the orders of the American government. A number of Lakota did not return to the United States, and their descendants remain near Wood Mountain to this day.

With the departure of the Lakota and the movement of First Nations peoples onto distant reserves away from the Cypress Hills, Fort Walsh grew less important. The NWMP headquarters was moved to Regina in 1882, and Fort Walsh was abandoned the following year.

The Fort Walsh site became the private ranch of David Wood and Wellington Anderson in 1893. Ranching became one of the most important industries in the Cypress Hills during and after the days of Fort Walsh, with some ranches established by ex-North West Mounted Police members.

In 1942, a land transfer took place which resulted in the grounds of Fort Walsh being returned to the ownership of the police, now under the name Royal Canadian Mounted Police. By 1943, construction had begun to rebuild some the buildings of old Fort Walsh site. The project became the Remount Ranch, a horse program for breeding the large black horses for the force, which have become known as an international symbol of Canada. This breeding program remained active until the core horse training by the R.C.M.P. was discontinued in 1966.

The buildings seen at Fort Walsh today were built by the R.C.M.P. in the 1940s. The Non-Commissioned Officers Barracks was built as a Centennial project in 1967, at the same time as the reconstructions of Farwell’s and Solomon’s trading posts. The buildings look very close to the ones used at Fort Walsh in the 1880s, and many had similar uses at both times in the site's history. However, not all the original Fort Walsh buildings were rebuilt in the 1940s. The R.C.M.P. only rebuilt the buildings needed to run a horse ranch successfully, therefore nearly half of the original buildings are missing.

The Remount Ranch was transferred by the R.C.M.P. to Parks Canada in 1968.