Sweetgrass is a port of entry very near the Canadian border. In 1890 a narrow-gauge railroad called the Turkey Track was built across the border between Great Falls and Lethbridge, and in 1900 Sweetgrass became a booming trade center as the dry land farmers arrived. The name comes from the abundance of "sweet" grass that grows around here. The town gave its name to the Sweetgrass Arch, a series of oil fields that extends south to Sunburst. (from Cheney's Names on the Face of Montana, Mountain Press Publishing Company)
