Colorado - Significance region: Local
| Nachtrieb-Kelly Ranch |
| National Fuel Company Store |
| National Hotel-Wolff Building |
| Navajo Hogan |
| Neef, Frederick W., House |
| Nettleton-Mead House |
| Neusteter Building |
| Newberry House |
| New Brick-The Brick Saloon |
| Newman Block |
| New Terrace |
| Niblock-Yacovetta Terrace |
| Nichols House |
| Nordlund House |
| Norman Apartments |
| North Cheyenne Canon Park |
| North End Historic District |
| North Fork Historic District |
| North Inlet Trail |
| North La Junta School |
| North Rim Road, Black Canyon of the Gunnison National Park |
| North Seventh Street Historic Residential District |
| North St. Vrain Creek Bridge |
| North Weber Street-Wahsatch Avenue Historic Residential District |
| Notch Mountain Shelter |
| Nunns, John Herbert, House |
| Nurses' Home |
| Ochsner Hospital |
| Ogden Theatre |
| Old Highland Business District |
| Old Ladore School |
| Old Livery Stable |
| Oltjenbruns Farm |
| Opera House Block/Central Block Building |
| Ore Processing Mill and Dam |
| Oriental Theater |
| Orlando Flats |
| Osgood Castle |
| Osgood-Kuhnhausen House |
| Ottesen Grain Company Feed Mill |
| Ouray City Hall and Walsh Library |
| Ouray Historic District |
| Our Lady of Guadalupe Church |
| Our Lady of Guadalupe Church and Medina Cemetery |
| Overland Cotton Mill |
| Owen Estate |
| Oxford Hotel |
| Oxford Hotel |
| Pacific Express Stable |
| Palace Hotel |
| Palmer Hall |
| Palmer, Judge Peter L. House |
| Paonia First Christian Church |
| Paramount Theater |
| Parish, Harvey J., House |
| Paris Mill |
| Park Hill |
| Park Theatre |
| Parry, William D., House |
| Patterson House |
| Pauline Chapel |
| Paulsen Farm |
| Pearce-McAllister Cottage |
| Pedro-Botz House |
| Peep O Day Park |
| People's Methodist Episcopal Church |
| Peoples Presbyterian Church |
| Peterson House |
| Peters Paper Company Warehouse |
| Petrelli-DelPizzo House |
| Petticrew Stage Stop |
| Phillips County Courthouse |
| Phillips, Harry and Lilly, House |
| Photography and Armament School Buildings, Lowry Air Force Base |
| Pierce-Haley House |
| Pike's Peak Grange No. 163 |
| Pine Hall |
| Pioneer Sod House |
| Pipe Line School |
| Pitkin County Courthouse |
| Pitkin Place Historic District |
| Placer Gulch Boarding House |
| Plaza Hotel |
| Pleasant Valley School |
| Pleasant Valley School |
| Plum Bush Creek Bridge |
| Poncha Springs Schoolhouse |
| Ponderosa Lodge |
| Potter Highlands Historic District |
| Powell and Blair Stone Ranch |
| Preston Farm |
| Pride of the Rockies Flour Mill |
| Provost Homestead-Herring Farm Rural Historic Landscape |
| Pryor, Frank, House |
| Pueblo Christopher Columbus Monument |
| Pueblo City Park Zoo |
| Pueblo Federal Building |
| Pueblo Mountain Park |
| Quaintance Block |
| Quaker Flour Mill |
Data from United States Park Service and Wikidata
