Boulders OHV Area, Upper Loop Professional Review and Guide
"A giant, natural roller-coaster park at the north end. Many additional miles of steep, narrow, twisting trails to explore. Washes are generally easy, but have a few rocky sections. The final wash, heading west toward Picacho Road, has one challenging spot.
The trail heads north, meandering in and out of sandy washes on the south end, then begins a gradual climb into the Hieroglyphic Mountains. Trails begin branching in all directions as hills get steeper and steeper. High points have incredible views in all directions, with roads as far as the eye can see."