I frequently go for a late afternoon motorbike ride in the dirt just past Green Valley (west side of St. George). Area is only a few miles from my house and a good variety of roads / tracks. Scenic bluffs look down on Bloomington and west to Utah Hill. Great (distant) views back to Snow Canyon and Pine Valley Mountain.
The other night I found signs for the mountain bike races of the Hunstman Senior Games. This was the end of long, rocky uphill. Lots of respect for seniors that rode their bikes up this hill!