In the Caribou - Targhee National Forest, the Sheep Driveway Trail #51 is a 28.5 mile route open to dirt bike riding. The entire route is open to offroad motorcycle riding, but only the first 5 miles are open to ATV riding.
To reach the trailhead from the intersecion of I-15 Business and US 26 in Idaho Falls, go north/east on US 26. Travel 21 miles to a left (north) on 175 Rd. E. Go 3 miles, travelling through the town of Poplar. Take a right on E. Heise Rd. This road goes through the town of Heise. Travel just over 2 miles and stay left on Kelly Canyon Rd. Go 3.5 miles to a left on 218 Rd. Travel 1.8 miles and turn right on Long Hollow Rd. (218.) Go 8.2 miles to a right on 226 Rd. Travel 3 mils to where the 226 Rd. intersects with Hilton Creek. This is the spot for ATVs to pick up the trail.
Overall, Sheep Driveway Trail is the 34th most popular dirt bike trail of all 53 dirt biking rides in Idaho.