These records include enumeration sheets and schedules for the Ninth and Tenth U.S. Censuses in Montana Territory. For 1870 there are enumeration sheets for the population of three districts of Lewis and Clarke County. Also for 1870 there are sheets for schedules 2, 3, 4, and 5 for ten of the eleven counties in the territory (Beaverhead, Choteau, Dawson, Deer Lodge, Gallatin, Jefferson, Lewis and Clarke, Madison Meagher, and Missoula; Big Horn is missing).

For 1880 there are enumeration sheets for all eleven counties in the territory (Beaverhead, Choteau, Custer [Big Horn in 1870], Dawson, Deer Lodge, Gallatin, Jefferson, Lewis and Clarke, Madison, Meagher, and Missoula). Also for 1880 there are sheets for schedules 3 (with special schedules) and 5, plus supplemental schedules.