Colorado - Area of significance: Architecture
| St. Mary's Catholic Church |
| Stockbridge House |
| Stocke-Walter Addition Historic District |
| Stolmes House |
| Stolte House |
| Stone House |
| Stonemen's Row Historic District |
| Stonington First Methodist-Episcopal Church |
| St. Patrick Mission Church |
| St. Paul African Methodist Episcopal (AME) Church |
| St. Paul's Church |
| St. Paul's English Evangelical Lutheran Church |
| Stranges Grocery |
| Streit, J. L., House |
| St. Stephen's Episcopal Church, 1881 |
| St. Stephen's Lutheran Church |
| St. Thomas Episcopal Church |
| Sumers Lodge |
| Summit Creek Ranger Station |
| Summit Lake Park |
| Sunshine School |
| Superintendent's Residence, Great Sand Dunes National Monument |
| Swallow Hill Historic District |
| Swanson, Gustav and Annie, Farm |
| Tallmadge and Boyer Block |
| Tammen Hall |
| Tarryall Rural Historic District |
| Tarryall School |
| Taylor Memorial Chapel |
| Tears-McFarlane House |
| Tego Brothers Drugstore-State National Bank of Louisville |
| Telephone Building |
| Teller House |
| Telluride Historic District |
| Temple Emanuel |
| Temple Emanuel |
| Temple Emanuel |
| Temple Emanuel |
| Terrace, The |
| Thede Farmhouse |
| The Petroleum Club Building |
| Thiede Ranch |
| Thomas, H. H., House |
| Thomas House |
| Thunder Lake Patrol Cabin |
| Ticknor Hall |
| Tigiwon Community House |
| Tilden School for Teaching Health |
| Timber Creek Campground Comfort Station No. 245 |
| Timber Creek Campground Comfort Station No. 246 |
| Timber Creek Campground Comfort Station No. 247 |
| Timberline Cabin |
| Tivoli Brewery Company |
| Tobasco Mine and Mill |
| Toll House |
| Tooke-Nuckolls House |
| Tower of Compassion |
| Tower of Memories |
| Town of Crested Butte |
| Townsend, Thomas B., House |
| Trail School, Old |
| Tramway Building |
| Trinchera Cave Archeological District |
| Trinity United Methodist Church |
| Trout Creek-Annex-Settele Ranch |
| Trujillo Homestead |
| Truscott Junior High School |
| Tutt Building |
| Twelfth Street Historic Residential District |
| Twin Lakes District |
| Twin Sisters Lookout |
| Two Buttes Gymnasium |
| Union Avenue Historic Commercial District |
| Union Depot |
| Union Pacific Railroad Julesburg Depot |
| Union Station |
| Union Warehouse |
| United Church of Christ of Highlandlake |
| United Methodist Church of La Junta |
| United States Air Force Academy, Cadet Area |
| Upper Brush Creek School |
| US Bureau of Reclamation Project Office Building |
| U.S. Courthouse and Federal Office Building |
| U.S. Customhouse |
| US National Bank |
| U.S. Post Office |
| U.S. Post Office and Federal Building |
| US Post Office and Federal Building-Canon City Main |
| US Post Office and Federal Building-Delta Main |
| US Post Office and Federal Building-Monte Vista Main |
| US Post Office and Federal Courthouse-Colorado Springs Main |
| US Post Office-Boulder Main |
| US Post Office, Federal Building, and Federal Courthouse-Sterling Main |
| US Post Office-Florence Main |
| US Post Office-Fort Morgan Main |
| US Post Office-Lamar Main |
| US Post Office-Manitou Springs Main |
| US Post Office-Montrose Main |
| US Post Office-Rifle Main |
| US Post Office-Trinidad Main |
Data from United States Park Service and Wikidata
