State Highway 91 is a stretch of highway in Colorado that connects Leadville to Interstate 70 at Copper Mountain.

SH 91 stretches 22.5 miles (36.2 km), starting at its southern junction with U.S. Highway 24 near Leadville. It runs northeast over Fremont Pass, passing the ghost town of Climax, home of the recently reopened Climax mine.

SH 91 ends at its junction with I-70 at Wheeler Junction. Since the development of the Copper Mountain Ski Area, Wheeler Junction is more commonly referred to as Copper Mountain.