A very nice trail just made by BLM, including switch backs up the mountain to the top of a heavily timbered ridge. Ride the ridge for a few miles then you've earned your turns back down.
How to get there:
Take highway 191 out of Lewistown, turn right onto Limekiln road for four miles. The road will dead end at the trailhead. Parking available.
Duvall Inn is at the trailhead and is a nice bed and breakfast.