Special Interest Areas (SIAs)


Unique or special resources are protected or enhanced through the designation of a Special Interest Area (SIA).  

Special interest areas can be designated to recognize a broader range of values than research natural areas, including botanical, geological, historical, paleontological, scenic, or zoological resources.  They may be allocated to protect and manage threatened, endangered or sensitive species and other elements of biological diversity, or for their motional significance, historic importance, scenic values or public popularity.  The size of the individual special interest area varies depending on the site-specific resource values and management emphasis. The GMUG National Forest contains a number of unusual or special resource characteristics.

Existing SIA




Slumgullion Slide




Dry Mesa Quarry




Ophir Needles




Alpine Tunnel




 Slumgullion Earthflow National Natural Landmark – The earthflow is a natural geologic process associated with the erosion of unstable geologic and soil features.  It includes approximately 900 acres of BLM land, 288 acres of National Forest System land and 100 acres of private land.  It is located two miles south of Lake City along the Silver Thread Scenic Byway.  The area is designated as a National Natural Landmark and is listed in the National Registry of Natural Landmarks.  The Colorado Natural Areas Program has also designated the earthflow as a Colorado Special Interest Area.

Dry Mesa Dinosaur Quarry Paleontological Site– the Dry mesa Quarry is a 55 acre site located within the Jurassic Morrison formation and contains fossils with a geologic age of approximately 150 million years.  The quarry is located 26 miles southwest of Delta on the Uncompahgre Plateau.  Excavation activity has yielded remains of many different kinds of extinct animals including partial skeletons of animals not previously known to science. The site was actively excavated from 1972-2000.

Ophir Needles – The Ophir Needles is a geologic formation within the San Juan Geographic area formed by alpine erosion etching out spectacular topographic spires from highly pointed intrusive rock.  This intrusion cuts sharply across a varied sequence of sedimentary and volcanic rocks and the discordant contracts are exceptionally displayed over a vertical range of about 1,000 feet.  This formation is 10 miles southwest of Telluride.  Ophir Needles is being nominated by the National Park Service for inclusion in the National Registry of Natural Landmarks.

Alpine Tunnel Historic District – The historic district is approximately 200 acres of National Forest System land.  It consists of three non-contiguous parcels of railroad that were built as part of the Denver, South Park, and Pacific Railroad.  With the tracks reaching 11,523 foot elevation, the Alpine Tunnel became the highest section of railroad in the world.  The Palisades parcel is known for its use of cribbing to stabilize the narrow points of the railroad route.  The district is located approximately 40 miles east of Gunnison along Forest Road 839.  The Alpine Tunnel has been nominated to the National Register of Historic Places.