As part of his vision for Canada, Galt was committed to finding industries that would bring settlers to the District of Alberta of the Northwest Territories.
Coincident with the building of the AR&CC line in 1890, the Galts received a Montana charter for the narrow gauge Great Falls and Canada Railway (GF&CR).
He was approached by Charles Ora Card of the Utah-based Church of Christ (Latter Day Saints), familiarly known as Mormons, who detailed his vision of using the local river systems for irrigation.
Under Brigham Young, the Mormons had established a thriving community centered on Salt Lake City and had pioneered and gained expertise in farming by irrigation in an area of deficient rainfall.
An agreement was reached with the Mormons in 1891, whereby they would lease 700,000 acres of land, bring in settlers, and provide labour for building the canal system.
An agreement was reached with the Government of Canada, whereby in an exchange of lands the AR&CC was able to assemble a solid block of 500,000 acres adjacent to the St. Mary River thus making large-scale irrigation feasible.
That same year the St. Mary’s River Railway Company was incorporated to provide access and serve the settlers benefiting from the irrigation system.