Rollins Pass (a.k.a. Corona Pass) sits above the popular ski areas around
Winter Park, between Winter Park and Rollinsville. The pass is traversed by
two unpaved roads, mostly the former roadbed of the Denver and Salt Lake
Railway which abandoned the route in 1928. The pass climbs about 2,800
feet in a little over 15 miles. Starting at around 9,000ft. and climbing to a
summit of 11,606ft.
You can travel completely across into Winter Park, or I recommend going up
and back. The route is very obvious and there are other 4x4 trails
connected to it. It's a hard packed rock/dirt road through terrific scenery
(especially in the fall).
Estimated ride time would be 3-5 hours up, and around 2 hours down.