The railway's arrival brought more and more settlers into the country. The Métis and native peoples along the North Saskatchewan River became concerned about the loss of their land and way of life. Government surveyors were re-mapping the land and threatening the Métis with eviction. The Métis hoped to obtain title to their traditional river front lots. However, when they petitioned Ottawa, their grievances went unheeded by an apparently indifferent government. Consequently, they decided to take the law into their own hands. At the invitation of Métis leader Gabriel Dumont, Louis Riel returned from his self-imposed exile in Montana to take up the Métis' land fight with the federal government.
Early in 1885, a provisional Métis government was set up, headed by Riel, with Dumont Commander-in-Chief of the Métis force. Big Bear's Crees supported the Métis cause. The Blackfoot, however, remained aloof from the conspiracy. Crowfoot, their chief, believed that the cause would fail, and in any case he and his people were reluctant to side with their traditional enemies, the Cree.
On March 13, 1885, a report from Battleford stated that a rebellion was likely to break out at any moment and the Cree would join the Métis. The northern detachments had to be reinforced. Commissioner Irvine received orders to proceed northward from Regina with all available men. Accompanied by four officers, 86 non-commissioned officers and men, and 66 horses, he made a forced march in bitter weather. Adroitly slipping past the insurgent outposts, the column reached Prince Albert, where they learned that looting had already begun and attacks on Prince Albert and Fort Carlton were imminent. Hostilities broke out before they reached Fort Carlton. On March 26, a severe clash took place near Duck Lake between 56 Mounted Policemen, 43 Prince Albert Volunteers, and a large body of Métis and Indians. Outnumbered by more than three to one, the Police-Volunteer force managed to retreat. Twelve of the 99 man force were killed in the action.
Duck Lake was an important psychological victory for the rebels, but one skirmish does not win the war. Hundreds of militia were on their way from Eastern Canada over the newly completed railway and within a few days an army had been assembled under Major-General F.D. Middleton's command. It moved forward to crush the rebels. In the military campaign which followed, the North-West Mounted Police played an important role. On May 12, 1885, after a series of indecisive engagements, the rebels were finally defeated at Batoche.