The Swamp Sparrow breeds from the Northwest Territories and eastern British Columbia east to Newfoundland and south to Nebraska, Iowa, the Great Lakes states, West Virginia, and Maryland. The species winters in the southeastern United States from New England and the Great Lake states south to Texas, Mexico and Northern Florida. The Swamp Sparrow is an uncommon migrant across Montana with three or fewer observations reported in a typical year (Mowbray 1997, MTNHP 2019).
For a comprehensive review of the conservation status, habitat use, and ecology of this and other Montana bird species, please see Marks et al. 2016, Birds of Montana.