Colorado - Criteria: C (architecture/engineering)
| Foster-Buell Estate |
| Foster, Ernest LeNeve, House |
| Four-Mile House |
| Fourth Church of Christ, Scientist |
| Fox Stone Barn |
| Francisco Plaza |
| Frantz, D. E., House |
| Frazier, R. T., House |
| Fruita Bridge |
| Fruita Museum |
| F Street Bridge |
| Fuller, Granville, House |
| Fuller, Montezuma, House |
| Galligan House |
| Garnethurst |
| Gas Creek School |
| Gast Mansion |
| Gates, Russell and Elinor, Mansion |
| Gebhard Mansion |
| Gem Lake Trail |
| General Electric Building |
| Genesee Park |
| Geneva Home |
| Georgetown Loop Railroad |
| German Evangelical Immanuel Congregational Church |
| Giddings Building |
| Ginacci House |
| Glacier Basin Campground Ranger Station |
| Glazier House |
| Glen Eyrie |
| Glenisle |
| Golconda Mine |
| Golden Cemetery |
| Golden High School |
| Goldfield City Hall and Fire Station |
| Gold Hill Historic District |
| Gold Miner Hotel |
| Gold Prince Mine, Mill and Aerial Tramway |
| Grace and St. Stephen's Episcopal Church |
| Grace Episcopal Church |
| Grace Episcopal Church |
| Grafton, The |
| Granada Bridge |
| Grand Lake Lodge |
| Grand River Ditch |
| Grand Valley Diversion Dam |
| Grant-Humphreys Mansion |
| Gray, Garret and Julia, Cottage |
| Great Western Sugar Company Effluent Flume and Bridge |
| Greeley Masonic Temple |
| Greeley Tribune Building |
| Greeley Union Pacific Railroad Depot |
| Greenwood Cemetery |
| Greenwood Lodge |
| Gregory, William J., House |
| Grimm, S. A., Block |
| Guerrieri-Decunto House |
| Gully Homestead |
| Gunnison River Bridge I |
| Gunnison River Bridge II |
| Gunnison Tunnel |
| Gwynne-Love House |
| Hagerman Mansion |
| Hallett, Samuel I., House |
| Hamburger, George, Block |
| Hammar, Benjamin, House |
| Hanigan-Canino Terrace |
| Hargreaves Homestead Rural Historic District |
| Harmony Mill |
| Harms Farm |
| Harris Park School |
| Hart, Wilson A., House |
| Haxby House |
| Hayden Ranch Headquarters |
| Hayden Rooming House |
| Hay's Ranch Bridge |
| Hazelhurst |
| Healy House |
| Heginbotham, W. E., House |
| Heister House |
| Helene Apartment Building |
| Hendrie and Bolthoff Warehouse Building |
| Henkel-Duke Mercantile Company Warehouse |
| Highland Park Historic District |
| Highland School |
| Highlands Masonic Lodge |
| Hiwan Homestead |
| Hog Park Guard Station |
| Holly City Hall |
| Holly Gymnasium |
| Holly Santa Fe Depot |
| Holly SS Ranch Barn |
| Holmes, David Hull, House |
| Holy Cross Abbey |
| Hopkins Farm |
| Hornbek House |
| Hose House No. 2 |
| Hotchkiss Methodist Episcopal Church |
| Hotel Boulderado |
| Hotel Colorado |
Data from United States Park Service and Wikidata
