You could go the north route on Hwy. 340, which eventually becomes Hwy. 30. The car rental maps do what they can to discourage this, but this is not a rough or dangerous road. It is a paved road in good condition the entire way, and the scenery is spectacular. I've ridden this route on a road bike many times, and it's one of my favorite rides in the world. If you can, give yourself time for some brief stops along the way. Including stops, this would take about 90 minutes.

The only caveat is a minor one (at least in my mind). There are a few switchbacks where the road is narrow, and it might be necessary to pull to the side and let an oncoming car pass. Also, some anxiety-prone people are spooked by vertigo.