The Rocky Mountain Rangers were one of the volunteer militia units raised in Canada's North West in response to the 1885 Rebellion. It was a body of mounted irregulars, mostly cowboys and ranchers from the area around Fort Macleod (District of Alberta), the headquarters of the NWMP located at the base of the foothills of the Rocky Mountains, about 150 miles to the west of Medicine Hat (in what was then the District of Assiniboia.) This unit is not to be confused with the present day Canadian Army Reserve unit The Rocky Mountain Rangers of Kamloops, British Columbia. Rather, it is the ultimate ancestor of the South Alberta Light Horse.
The campaign against Riel in North West Canada was put under the command of Major-General F. Middleton, a British born commander of the Canadian Militia, who had seen extensive military service. Middleton did not trust the newly formed Canadian Militia cavalry troops from Eastern Canada, as they had little experience, and had no feel for the ground on which they were to patrol. Instead, Middleton took the advice given to him by the Prime Minister, John A. Macdonald, who suggested that he recruit local troops, who would be "much more serviceable than town-bred men who compose our cavalry."
The main purpose of the RMR was to fight as a mounted cavalry against either discontented Canadian First Nations, or border-jumping American warriors. They were to supplement patrols of the North-West Mounted Police (NWMP) and provide security to the railroad construction crews.
Commanded by John Stewart, a rancher turned militia officer from the Fort Macleod area, the Rocky Mountain Rangers was a microcosm of local citizens, stockmen, trappers, politicians and discharged Mounties hammered into an irregular cavalry unit.
Stewart was directed in early March 1885 to organize “four units of Rocky Mountain Rangers”. Stewart was in immediate communication by telegraph with former military contacts back home, as he was visiting family in Ottawa when news of the Metis uprising reached him. He quickly began the task of organizing the units.
There were 114 members led by Major Stewart. The members were to supply their own mounts, tack and sidearms but since this last resulted in a variety of questionable weapons, Major Stewart arranged for the issuance of some NWMP rifles including a few of the obsolete single shot Snider-Enfield .577 and forty of the new 1876 .45-75 Winchesters.
Number 3 Troop of the RMR remained in the Fort Macleod area as a Home Guard, but Number One and Two Troops were sent to Medicine Hat, a very strategic point where the newly built Canadian Pacific Railway bridges the South Saskatchewan River - the largest physical obstacle on its entire route between Winnipeg and the Rocky Mountains. Seizure or destruction of the bridge at that point would have played havoc with continued effective use of the railway, which was of immense help in transporting men, equipment and supplies.