| State | Office Code | ACEC Name | Designation Date | Size (Acres) | Reason for Designation | Land Use Plan |
| CO | 100 | Cross Mountain Canyon | 4-30-89 | 3,000 | Scenic, Geological | Little Snake |
| CO | 100 | Lookout Mountain | 4-30-89 | 6,500 | Botanical | Little Snake |
| CO | 100 | Irish Canyon | 4-30-89 | 11,680 | Scenic, Botanical | Little Snake |
| CO | 100 | Limestone Ridge | 4-30-89 | 1,350 | Botanical | Little Snake |
| CO | 110 | Deer Gulch | 7-1-97 | 1,810 | Botanical | White River |
| CO | 110 | Lower Greasewood Creek | 7-1-97 | 210 | Botanical | White River |
| CO | 110 | South Cathedral Bluffs | 7-1-97 | 1,330 | Botanical | White River |
| CO | 110 | Dudley Bluffs | 7-1-97 | 1,630 | Botanical | White River |
| CO | 110 | Yanks Gulch/Upper Greasewood Creek | 7-1-97 | 2,680 | Botanical | White River |
| CO | 110 | Raven Ridge | 7-1-97 | 4,980 | Botanical, Paleontological | White River |
| CO | 110 | Ryan Gulch | 7-1-97 | 1,440 | T&E Plants | White River |
| CO | 110 | White River Riparian | 7-1-97 | 950 | Botanical | White River |
| CO | 110 | Coal Oil Rim | 7-1-97 | 3,210 | Botanical | White River |
| CO | 110 | Moosehead Mountain | 7-1-97 | 8,940 | Botanical, Cultural | White River |
| CO | 110 | Oil Spring Mountain | 7-1-97 | 18,260 | Botanical | White River |
| CO | 110 | Black's Gulch | 7-1-97 | 800 | Paleontological | White River |
| CO | 110 | Coal Draw | 7-1-87 | 1,840 | Paleontological | White River |
| CO | 110 | East Douglas Creek | 7-1-97 | 47,610 | Botanical | White River |
| CO | 110 | Duck Creek | 7-1-97 | 3,430 | T&E Plants, Cultural | White River |
| CO | 120 | North Park Phaceila | 12-19-84 | 300 | Botanical | Kremmling |
| CO | 120 | Ammonite Site RNA | 12-19-84 | 160 | Paleontological | Kremmling |
| CO | 150 | Needle Rock | 7-26-89 | 80 | Scenic | Uncompahgre |
| CO | 150 | Fairview | 7-26-89 | 377 | Botanical | Uncompahgre |
| CO | 150 | Escalante Canyon | 7-26-89 | 1,895 | Botanical, Scenic | Uncompahgre |
| CO | 150 | Adobe Badlands | 7-26-89 | 6,783 | Recreation | Uncompahgre |
| CO | 150 | San Miguel River | 3-23-93 | 20,964 | Riparian, Scenic | San Juan/San Miguel |
| CO | 150 | Tabeguache Creek | 9-30-85 | 440 | Scenic | San Juan/San Miguel |
| CO | 160 | American Basin | 2-5-93 | 1,595 | Scenic | Gunnison |
| CO | 160 | Red Cloud Peak | 2-5-93 | 5,947 | T&E Species | Gunnison |
| CO | 160 | Slumgullion NNL | 2-5-93 | 1,407 | Geological | Gunnison |
| CO | 160 | South Beaver Creek | 2-5-93 | 4,565 | T&E Plants | Gunnison |
| CO | 160 | West Antelope Creek | 2-5-93 | 28,215 | Wildlife | Gunnison |
| CO | 160 | Dillon Pinnacles | 2-5-93 | 532 | Geological | Gunnison |
| CO | 170 | Anasazi Culture | 9-30-85 | 156,000 | Cultural Resources | San Juan/San Miguel |
| CO | 210 | Rio Grande | 12-18-91 | 2,830 | Recreation, Scenic | San Luis |
| CO | 210 | Rajadero Canyon | 12-18-91 | 3,632 | T&E Plants | San Luis |
| CO | 210 | Elephant Rocks | 12-18-91 | 1,338 | T&E Plants | San Luis |
| CO | 210 | Blanca Wildlife Habitat Area | 12-18-91 | 8,600 | Wildlife, Recreation | San Luis |
| CO | 220 | Trickle Mountain | 12-18-91 | 44,521 | Wildlife | San Luis |
| CO | 210 | Cumbres and Toltec Railroad | 12-18-91 | 3,824 | Historic, Scenic | San Luis |
| CO | 210 | Los Mogotes | 12-18-91 | 33,456 | Wildlife | San Luis |
| CO | 210 | San Luis Hills/Flattop | 12-18-91 | 29,261 | Scenic | San Luis |
| CO | 210 | Sand Castle | 12-18-91 | 3,595 | Cultural | San Luis |
| CO | 200 | Arkansas Canyonlands | 4-16-96 | 23,921 | Recreation, Scenic, T&E Plants | Royal Gorge |
| CO | 200 | Beaver Creek | 4-16-96 | 12,081 | Scenic, Wildlife | Royal Gorge |
| CO | 200 | Browns Canyon | 4-16-96 | 11,697 | Scenic, Wildlife | Royal Gorge |
| CO | 200 | Cucharas Canyon | 4-16-96 | 1,866 | Scenic, Cultural | Royal Gorge |
| CO | 200 | Droney Gulch | 4-16-96 | 705 | T&E Plants | Royal Gorge |
| CO | 200 | Garden Park NNL | 4-16-96 | 2,728 | Paleontology, Historic | Royal Gorge |
| CO | 200 | Grape Creek | 4-16-96 | 15,978 | Scenic | Royal Gorge |
| CO | 200 | Mosquito Pass | 4-16-96 | 4,036 | Scenic, T&E Plants | Royal Gorge |
| CO | 200 | Phantom Canyon | 4-16-96 | 6,096 | Recreation, Historic | Royal Gorge |
| CO | 130 | Rough Canyon | 1-30-87 | 1,470 | Botanical | Grand Junction |
| CO | 130 | Pyramid Rock | 1-30-87 | 470 | Botanical | Grand Junction |
| CO | 130 | Rabbit Valley RNA | 1-30-87 | 280 | Paleontology | Grand Junction |
| CO | 130 | Badger Wash | 1-30-87 | 1,520 | Botanical | Grand Junction |
| CO | 130 | Unaweep Seep RNA | 1-30-87 | 37 | Fish & Wildlife | Grand Junction |
| CO | 130 | Fruita Paleo Quarry | 1-30-87 | 280 | Paleontology | Grand Junction |
| CO | 130 | The Palisade | 1-30-87 | 19,178 | Geological | Grand Junction |
| CO | 130 | Gunnison Gravels | 1-30-87 | 5 | Geological | Grand Junction |
| CO | 140 | Thompson Creek | 1-30-84 | 4,286 | Recreation | Glenwood Springs |
| CO | 140 | Bull Gulch | 1-30-84 | 10,214 | Recreation | Glenwood Springs |
| CO | 140 | Blue Hill | 1-30-84 | 4,178 | Cultural | Glenwood Springs |
| CO | 140 | Lower Colorado River | 1-30-84 | 9,000 | Riparian | Glenwood Springs |
| CO | 140 | Debris Hazard | 1-30-84 | 7,126 | Natural Hazard | Glenwood Springs |
| CO | 140 | Deep Creek | 1-30-84 | 2,470 | Recreation | Glenwood Springs |
Common Abbreviations: ONA = Outstanding Natural Area; RNA = Research Natural Area ; NNL = National Natural Landmark
COLORADO TOTALS: 66 Areas of Critical Environmental Concern comprising 621,286 acres. This amounts to approximately 7 1/2% of the public lands.
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