To access the Pioneer Mountain Bike Trail, drive or ride up Ephraim Canyon road approximately 5.4 miles past the end of the pavement (about 1/2 mile past Lake Hill Campground) and you'll see a dirt road on the left-hand side of the canyon road (N39.32633 W111.49604, Elevation 8,392). This is a great place to unload if you have chosen to drive.
From here it is approximately 3/4 mile decent on a primitive road. At this point you'll see a small sign on the left that says Pioneer Trail
. Turning left here will put you on approximately 3 miles of singletrack. Eventually the trail intersects the main canyon road at either GPS N39.33947 W111.51664 or N39.33698 W111.52119 (Parking at the National Forest Boundary).
If you ride down the canyon road approximately 1/2 mile, you can cut off and ride another 3 1/2 miles of singletrack on the famous Flume trail. (N39.33766 W111.52684, Elevation 6,637)