Colorado - Criteria: C (architecture/engineering)
| S.P.M.D.T.U. Concilio Superior |
| Spratlen-Anderson Wholesale Grocery Company-Davis Brothers Warehouse |
| Spring Creek Bridge |
| Springfield Schoolhouse |
| Spring Valley School |
| Spruce Hall |
| Spruce Lodge |
| Squires-Tourtellot House |
| St. Andrews Episcopal Church |
| Stanley Arms |
| Stanley Hotel |
| St. Anthony's Roman Catholic Church |
| Star Journal Model Home |
| Starr Manor |
| State Armory |
| Staunton Ranch Rural Historic Landscape |
| St. Charles Bridge |
| St. Dominic's Church |
| Steamboat Apartments |
| Steamboat Laundry Building |
| Steamboat Springs Depot |
| Stearns House |
| St. Elizabeth's Church |
| St. Elizabeth's Retreat Chapel |
| St. Elmo Historic District |
| Sterling Public Library |
| Sterling Union Pacific Railroad Depot |
| Stickney, Charles H., House |
| St. Ignatius Loyola Church |
| St. James Episcopal Church |
| St. John's Cathedral |
| St. John's Greek Orthodox Church |
| St. Joseph's Roman Catholic Church of Denver |
| St. Mark's Parish Church |
| St. Mark United Presbyterian Church |
| St. Mary's Catholic Church |
| Stockbridge House |
| Stolmes House |
| Stolte House |
| Stone House |
| Stonington First Methodist-Episcopal Church |
| St. Patrick Mission 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. Thomas Episcopal Church |
| Sumers Lodge |
| Summit Lake Park |
| Sunken Gardens |
| Sunshine School |
| Superintendent's Residence, Great Sand Dunes National Monument |
| Surface Creek Livestock Company Silos |
| Sutherland Bridge |
| Tallmadge and Boyer Block |
| Tarryall School |
| Taylor Memorial Chapel |
| TBM Avenger Aircraft N53503 |
| 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 |
| Thomas, H. H., House |
| Thomas House |
| Thunder Lake Patrol Cabin |
| Thunder Lake Trail-Bluebird Lake Trail |
| Ticknor Hall |
| Tigiwon Community House |
| 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 |
| Toll House |
| Tonahutu Creek Trail |
| Tooke-Nuckolls House |
| Tower of Memories |
| Town of Crested Butte |
| Townsend, Thomas B., House |
| Trail Ridge Road |
| Trail School, Old |
| Tramway Building |
| Trinchera Cave Archeological District |
| Trinity United Methodist Church |
| Trujillo Homestead |
| Tutt Building |
| Twin Lakes District |
| Twin Sisters Lookout |
| Two Buttes Gymnasium |
| Union Avenue Historic Commercial District |
| Union Depot |
| Union Pacific Railroad Julesburg Depot |
Data from United States Park Service and Wikidata
