Montana - Significance region: Local
| Brooks Hotel |
| Brotherhood of Locomotive Engineers Hall |
| Browne's Bridge |
| Brunswick Hotel |
| Bruyer Granary |
| B Street District |
| Buck, Charles Amos, House |
| Buck, Fred, House |
| Bull Head Lodge and Studio |
| Burgess Garage |
| Burke, Thomas H., House |
| Busch House |
| Buttelman Ranch |
| Calvary Episcopal Church |
| Cammock's Hotel |
| Camp Paxson Boy Scout Camp (24MO77) |
| Camp Senia Historic District |
| Canyon Creek Charcoal Kilns |
| Caple, W. T., House |
| Carbella Bridge |
| Carlton Community Church |
| Carnegie Public Library |
| Carnegie Public Library |
| Carriage House Historic District |
| Cascade County Courthouse |
| Cat Creek Oil Field Sign |
| Cattle Queen Snowshoe Cabin |
| Chadwick House |
| Cheever-Cain Ranch |
| Chicken Creek Farmstead Historic District |
| Chief Mountain Border Station and Quarters |
| Childs Carriage House |
| Child, W. C., Ranch |
| Chivers Memorial Church |
| Christ Episcopal Church and Rectory |
| Christie, Thomas J., House |
| City Hall |
| City Water Department |
| Clack, H. Earl, House |
| Clack, H. Earl, Service Station |
| Clark-Cardwell House |
| Clark, Jennie, House |
| Coal Creek Patrol Cabin |
| Cochran, William, House |
| Colburn House |
| Cold Springs Ranch House |
| Coleman, William E., House |
| Collins, James V., House |
| Comertown Historic District |
| Commercial District |
| Commercial District |
| Como School |
| Conrad City Hall |
| Continental Oil Company Filling Station |
| Continental Oil Company Warehouse and Garage |
| Conway House |
| Cook, Calvin and Maggie, House |
| Cooke City Store |
| Cook, Wilbur, House |
| Cooper Park Historic District |
| Coram Hotel, The |
| Corey House |
| Cornelius Hedges Elementary School |
| Cottonwood Creek Bridge |
| Cottonwood School |
| Courthouse Historic District |
| Crail Ranch Buildings |
| Cramer, Martin, House |
| Crow Creek Water Ditch |
| Crump-Howard House |
| Crum, William C., House |
| Crystal Ice & Fuel Company |
| Culver Studio |
| Cuthbert, D. H., House |
| Daly, Marcus, Memorial Hospital |
| Daniels County Courthouse |
| Daniels, Mansfield A., House |
| Dave's Texaco |
| Davidson Building |
| Dean, A. J., House |
| Dean School |
| DeBorgia Schoolhouse |
| Deer Lodge American Women's League Chapter House |
| Deer Lodge Central Business Historic District |
| Deer Lodge County Courthouse |
| DeNayer House |
| DeSmet Schoolhouse |
| Detention Hospital |
| Dillon City Hall Historic District |
| Dillon City Library |
| Dixon-Duncan Block |
| Dokken-Nelson Funeral Home |
| Doncaster Round Barn |
| Donovan-Mayer House |
| Dorsey Grocery and Residence |
| Double Arrow Lodge |
| Draft Horse Barn, Fergus County Fairgrounds |
| Drew, J. W., Grain Elevator |
| Drinkenberg's, F. H., First Home |
| Driver’s Saloon and Café |
Data from United States Park Service and Wikidata
