Colorado - Significance region: Local
| Queen of Heaven Orphanage Summer Camp |
| Railway Exchange Addition and Railway Exchange New Building |
| Rankin Presbyterian Church |
| Ray Apartments Buildings |
| Raymond, Wilbur S., House |
| Red Cliff Bridge |
| Red Rocks Park District |
| Reno Park Addition Historic District |
| Rhoades House |
| Rialto Theater |
| Rice, Ida M., House |
| Rice, Ward, House |
| Richards Mansion |
| Richthofen Castle |
| Rico City Hall |
| Riede's City Bakery |
| Rifle Bridge |
| Rim Rock Drive Historic District |
| Rimrock School |
| Rio Grande Southern Railroad Engine No. 20 |
| Rio Grande Southern Railroad, Motor No. 6 |
| Rio Grande Southern Railroad Trout Lake Water Tank |
| Rito Seco Creek Culvert |
| Riverside Cemetery |
| Robertson, T. H., House |
| Robidoux, M.J. Lavina, House |
| Robinson House |
| Robinson House |
| Rochester Hotel |
| Rock Creek Farm Rural Historic District |
| Rock Island Snow Plow No. 95580 |
| Rockland Community Church and Cemetery |
| Rock Ledge Ranch-Franzel Ranch |
| Rocky Ford Post Office |
| Rocky Mountain Bank Note Company Building |
| Rocky Mountain Hotel |
| Rocky Mountain Mammoth Mine |
| Rocky Mountain National Park Utility Area Historic District |
| Romano, Samuel and Albina, House |
| Romeo Block |
| Rood Candy Company Building |
| Rooney Ranch |
| Root, Amos H., Building |
| Roselawn Cemetery |
| Rose Lime Kiln |
| Rosemount |
| Ross-Broadway Branch, Denver Public Library |
| Rossonian Hotel |
| Roth, Henry, House |
| Rouch Gulch Bridge |
| Rourke, Eugene, House |
| Rourke Ranch Historic District |
| Routt County National Bank Building |
| Roxborough State Park Archaeological District |
| Roy's Ruin |
| Ruble-Orendorf Mercantile |
| Russell-Graves House |
| Russell Gulch I.O.O.F. Hall No. 47-Wagner and Askew |
| Ruth Memorial Methodist Episcopal Church |
| Sacred Heart Catholic Church |
| Sacred Heart Church |
| Sacred Heart Orphanage |
| Saddlehorn Caretaker's House and Garage |
| Saddlehorn Comfort Station |
| Saddlehorn Utility Area Historic District |
| Saguache Downtown Historic District |
| Saguache Flour Mill |
| Saguache School and Jail Buildings |
| Saint Philomena Catholic Parish School |
| Saint Thomas Theological Seminary |
| Salazar, A.A., House |
| Salida Downtown Historic District |
| Salida Livestock Commission Company |
| Salina School |
| Sandbeach Lake Trail |
| Sandstone Ranch |
| San Juan Avenue Historic District |
| San Luis Bridge |
| San Luis Southern Railway Trestle |
| San Rafael Historic District |
| Santa Fe Avenue Bridge |
| Santa Fe Railway Manzanola Depot |
| Santa Fe Railway Water Tank |
| Sargents Water Tank, Denver and Rio Grande Railroad, Western Line |
| Satank Bridge |
| Schleier, George, Mansion |
| Schlessinger House |
| Schlichter, E.A., House |
| Schmidt, George, House |
| Schnell Farm |
| Sciumbato, Daniel, Grocery Store |
| Scott Apartments and Garage, The |
| Second Midland School |
| Sedgwick County Courthouse |
| Serpents Trail |
| Seventeen Mile House |
| Shadow Mountain Lookout |
| Shadow Mountain Trail |
| Shaffer, Henry K. and Mary E., House |
| Shaffer, John C., Barn |
Data from United States Park Service and Wikidata
