It is approximately 40 miles (64 km) long and is located in Gunnison, Pitkin and Garfield counties in Colorado, United States.

The Crystal Valley historically was a seasonal home and hunting ground of the Parianuche and Yampa bands of the Ute people.

It rises in northern Gunnison County on the north side of Schofield Pass near the Maroon Bells and passes through the ghost town of Crystal City, still inhabited by a few summer residents and known for the Crystal Mill photographic attraction.

State Highway 133 follows the river along much of its route from Carbondale until several miles below Marble, where 133 turns southwest and crosses McClure Pass towards Paonia and Delta, Colorado.

Although it is locally known as a fishing and hiking attraction the unpaved and largely un-maintained mining road, designated Gunnison County Road 3 on Mapquest, is nearly impassable to vehicles other than ATVs and off-road motorcycles.