West of Vernal and northwest of Roosevelt, the Petty Mountain Loop is a 14 mile route open to mountain bikers and off-road motorcycle riders. Keep an eye out for active logging operations and livestock ranging. This is part of the Yellowstone off-road motorcycle trail system. The other half of the trail system is the Dry Gulch Loop.
To reach the trailhead from Roosevelt, travel north along UT 87 to Mountain Home, then north to Yellowstone along FR 119. A parking lot and trailhead are located in the lower Hells Canyon area just past the Ashley National Forest boundary. The trail begins in the lower Hells Canyon area of Yellowstone Canyon, along FR 119. At its junction with FR 196, head west along a good dirt road. Continue along FR 196 as it climbs and winds its way towards Petty Mountain. Pedal across Flea Flat and through Bear Park. There is a spur there to Lake Fork Mountain. At Mill Park, the trail bends northeast and intersects FR 227 at Mill Spring. Take a right onto FR 227 and head southeast down through Hells Canyon back to the trailhead.
Overall, Petty Mountain Loop is the 57th most popular dirt bike trail of all 68 dirt biking rides in Utah.