For forest service trails, the Pole Canyon system offers some pretty awesome DH. Like in all national forests, it's not hard to find rough, loose, and steep trail to get the muscles pumping. However, you can also ride jumps and drops on trails like Squaw Peak Overlook. Intermediate riders, on the other hand, will enjoy the lower portion of the canyon, which is filled with mellower, flowy routes. The best part is that all of this is located conveniently close to the Provo area.