The north side has the steepest grade of any continuously paved road in Colorado (9%),[2] but the pass does not close often in winter because snowplows clear the route regularly during this season.

It has a few switchbacks and tight spots, but other than that, most travelers will find it an easy, scenic route.

Technically speaking, the current highway does not traverse the true Slumgullion Pass, which lies just off the highway on the ridge between Cebolla Creek and the Lake Fork of the Gunnison River, at an elevation of about 11,300 ft (3,400 m).

[3] As a result of a realignment several decades ago (evident by comparing USGS topographic maps of different vintages), the road now takes a shorter but somewhat higher route as it travels east and south from this spot toward Spring Creek Pass.

The Slumgullion Slide began about 700 years ago when weak volcanic tuff and breccia on the southern flank of Mesa Seco slumped several miles down the steep mountainside.