Driving Roads / Trail Ridge Road

The 48-mile Trail Ridge Road tops out at 12,183 feet, the highest continuous paved road in the U.S., with miles of driving above the tree line. It runs about 48 miles along US-34 (Rocky Mountain National Park) in Colorado. Drive time: about 1 h 45 min one way.
Best time to go: Summer to early fall; the high section closes for snow from about October to May.

Sources: Length · High point · Best time. Drive time is the route time for the mapped route without stops, from Mapbox.
Record the above-treeline crossing and keep it in your drive log. A slow scenic-cruise road where the altitude and views matter more than speed.
Seasonal closures, high winds and sudden weather are common above the tree line; drive slowly and watch for wildlife and stopped sightseers.
Open Road keeps every drive: the route on a map, the time and the distance. On iPhone and Android.