Montana - Criteria: C (architecture/engineering)
| Medicine Point Lookout |
| Merrill Avenue Historic District |
| Metcalf House |
| Methodist Church of Alberton |
| Methodist Episcopal Church |
| Methodist Episcopal Church |
| Methodist Episcopal Church and Parsonage |
| Methodist Episcopal Church of Anaconda |
| Methodist-Episcopal Church of Marysville |
| Methodist Episcopal Church South |
| Miles City Waterworks Building and Pumping Plant Park |
| Miles, George M., House |
| Miller, J. K., Homestead |
| Mill House |
| Milwaukee Depot |
| Milwaukee Road Historic District |
| Mineral Peak Lookout |
| Miners Union Hall |
| MISCO Grain Elevator |
| Missoula County Courthouse |
| Missoula Downtown Historic District |
| Missoula Laundry Company |
| Missouri River Bridge |
| Model Laundry and Apartments |
| Modern Hotel |
| Moncure Tipi |
| Montana Deaf and Dumb Asylum |
| Montana State Arsenal, Armory and Drill Hall |
| Montana State Capitol Building |
| Montana State Training School Historic District |
| Montana State University Historic District |
| Montana Territorial and State Prison |
| Montana Veterans and Pioneers Memorial Building |
| Montgomery Ward |
| Morel Bridge |
| MORNING EAGLE (carvel-planked wooden vessel) |
| Morr, Philip and Ella, House |
| Mossman Overpass |
| Moss, Preston B., House |
| Mountain States Telephone and Telegraph Company |
| Mountain View Cemetery |
| Mount Brown Fire Lookout |
| Mrs. Lydia McCaffery's Furnished Rooms |
| Natural Pier Bridge |
| Neihart School |
| New Brunswick House, The |
| Newman House |
| Norby House |
| North, Austin, House |
| Northeast Entrance Station |
| North Entrance Road Historic District |
| Northern Hotel |
| Northern Montana State Fairground Historic District |
| Northern Pacific Railroad Depot |
| Northern Pacific Railroad Depot-Fromberg |
| Northern Pacific Railway Depot |
| Norton, W. H., House |
| Norwegian Evangelical Lutheran Church and Parsonage |
| Numa Ridge Fire Lookout |
| Nyack Ranger Station Historic District |
| O'Brien, William, House |
| O'Donnell, I. D., House |
| Olive Hotel |
| Oliver Building |
| Olsen House |
| Olsson, Don E., House and Garage |
| O'Neil Lumber Company Office |
| Orange Street Tunnel |
| Oregon Short Line Passenger Depot |
| OTO Homestead and Dude Ranch |
| Outlook Depot |
| Palace Hotel |
| Panton House |
| Parberry Block East |
| Parmly Billings Memorial Library |
| Pass Creek School |
| Pass Creek Snowshoe Cabin |
| Pelton, Charles and Gladys, House |
| Peoples' Congregational Church |
| Peterson House |
| Petroglyph Canyon |
| Philipsburg Historic District |
| Pine Apartments |
| Pine Butte School |
| Ping, J. J., House |
| Point of Rocks Historic Transportaion Corridor |
| Polebridge Ranger Station Historic District |
| Polebridge to Numa Ridge Phoneline |
| Polson Feed Mill |
| Pope, Francis and Hannah, House |
| Popham Ranch |
| Porter Flats Apartments |
| Porter Ranch Barn |
| Powder House |
| Powder River Bridge |
| Power, C. B., Bungalow |
| Prescott, Clarence R., House |
| Prescott Commons |
| Preston House |
| Ptarmigan Tunnel |
Data from United States Park Service and Wikidata
