Montana - Area of significance: Architecture
| Bright House |
| Bright-Thompson-Lewis House |
| Brinks House |
| Broadwater, Charles A., House |
| Brooder, Frank, House |
| Brooks Hotel |
| Brotherhood of Locomotive Engineers Hall |
| Brunswick Hotel |
| Bruyer Granary |
| B Street District |
| Buck, Charles Amos, House |
| Buck, Fred, House |
| Bull River Guard Station |
| Burke, Thomas H., House |
| Burlingame School |
| Busch House |
| Butte, Anaconda and Pacific Railway Historic District |
| Buttelman Ranch |
| Byam, Dr. Don L., House |
| Calvary Episcopal Church |
| Cammock's Hotel |
| Camp Paxson Boy Scout Camp (24MO77) |
| Camp Senia Historic District |
| Caple, W. T., House |
| Carlton Community Church |
| Carnegie Public Library |
| Carnegie Public Library |
| Carnegie Public Library |
| Carriage House Historic District |
| Cascade County Courthouse |
| Castle Rock Lodge |
| Cathedral of Saint Helena |
| Cattle Queen Snowshoe Cabin |
| Chadwick House |
| Chicago, Milwaukee and St. Paul Passenger Depot |
| Chico Hot Springs |
| Chief Mountain Border Station and Quarters |
| Childs Carriage House |
| Child, W. C., Ranch |
| Chouteau County Courthouse |
| 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, Charles W., Mansion |
| Clark, Jennie, House |
| Clark, W. A., Mansion |
| Club Moderne |
| Coal Creek Patrol Cabin |
| Cochran, William, House |
| Colburn House |
| Cold Springs Ranch House |
| Coleman, William E., House |
| Collins, James V., House |
| Collins, Timothy Edwards, Mansion |
| Commercial District |
| Commercial District |
| Como School |
| Conrad, Charles E., Mansion |
| Conrad City Hall |
| Continental Oil Company Filling Station |
| Conway House |
| Cook, Calvin and Maggie, House |
| Cooke City Store |
| Cook Farm |
| Cook, Wilbur, House |
| Cooper Park Historic District |
| Corey House |
| Cornelius Hedges Elementary School |
| Cottonwood School |
| Cougar Peak Lookout |
| Courthouse Historic District |
| Crail Ranch Buildings |
| Cramer, Martin, House |
| Crocker-Jarvi Homestead |
| Cross Ranch Headquarters |
| Crum, William C., House |
| Crystal Ice & Fuel Company |
| Cut Bank Ranger Station Historic District |
| Cuthbert, D. H., House |
| Daly, Marcus, Memorial Hospital |
| Daniels County Courthouse |
| Dave's Texaco |
| Davidson Building |
| Dayton State Bank |
| Dean, A. J., House |
| Dean School |
| Deer Lodge American Women's League Chapter House |
| Deer Lodge Central Business Historic District |
| Deer Lodge County Courthouse |
| DeNayer House |
| DESMET (boat) |
| DeSmet Schoolhouse |
| Dillon City Hall Historic District |
| Dillon City Library |
| Dixon-Duncan Block |
| Doe, M. E., House |
Data from United States Park Service and Wikidata
