Montana - Significance region: Local
| North Elevation Historic District |
| Northern Hotel |
| Northern Pacific Railroad Depot |
| Northern Pacific Railroad Depot-Fromberg |
| Northern Pacific Railroad Settling Tanks |
| Northern Pacific Railway Depot |
| Northern Pacific Warehouse |
| North Fork Road |
| Northside Missoula Railroad Historic District |
| Northside School |
| North Tracy Avenue Historic District |
| Norton, W. H., House |
| Norwegian Evangelical Lutheran Church and Parsonage |
| Nutting Rental |
| O'Brien, William, House |
| Old U.S. Highway 91 Historic District |
| Olive Hotel |
| Oliver Building |
| Olsen House |
| Olsson, Don E., House and Garage |
| O'Neil Lumber Company Office |
| Oregon Short Line Passenger Depot |
| Outlook Depot |
| Palace Hotel |
| Panton House |
| Paradise School |
| Parberry Block East |
| Parrot Mine Shops Complex |
| Pass Creek School |
| Paxson, Edgar, House |
| Pease's, George, Second Store |
| Pelton, Charles and Gladys, House |
| Peoples' Congregational Church |
| Peterson House |
| Peterson Place |
| Phillips County Carnegie Library |
| Pine Apartments |
| Pine Butte School |
| Ping, J. J., House |
| Pioneer Park |
| Polebridge to Numa Ridge Phoneline |
| Polson Feed Mill |
| Pony Historic District |
| Pope, Francis and Hannah, House |
| Popham Ranch |
| Porter Flats Apartments |
| Potomac School |
| Powder House |
| Powder River Bridge |
| Prescott, Clarence R., House |
| Prescott Commons |
| Preston House |
| Quaw, Thomas, House |
| Quinn's Garage |
| Rahrer, Francis, House |
| Railroad Depot |
| Rainbow Conoco |
| Ramsay Historic District |
| Randall, Harry E., House |
| Ravalli County Courthouse |
| Raymond Grain Elevators Historic District |
| Rea School |
| Red Lodge Brewing Company-Red Lodge Canning Company |
| Red Lodge Commercial Historic District |
| Reed's Fort Post Office |
| Reese Creek School |
| Regan, Thomas P., Cabin |
| Regis Grocery |
| Reid House |
| Reid-Kent House |
| Reno Apartments |
| Residential District |
| Ressler, Guy, Homestead House |
| Rialto Theater |
| Rinard House |
| Ringleberg, Cornelius, House |
| Riverside Park, Laurel |
| River View Dairy Barn |
| Robbers Roost |
| Roberts Building |
| Robworth Apartments |
| Rock Creek Ranger Station Historic District |
| Rock Creek State Bank |
| Rocky Valley Lutheran Church |
| Roes Creek Campground Camptender's Cabin |
| Rogers House |
| Rolfson House |
| Roose-Eckelberry House |
| Rosebud County Courthouse |
| Rosebud County Deaconess Hospital |
| Roundup Central School |
| Rouse House |
| Ruby Theatre |
| Ruffatto School |
| Rundle Building |
| Russell, Charlie and Nancy, Honeymoon Cabin |
| Russell School |
| Ruth, Harold and Marion, House |
| Ryan's, John, House |
| Sacajawea Hotel |
Data from United States Park Service and Wikidata
