Prescott's Secret Trails...all kinds of stuff. Really easy to get lost. The only trail marked is 332. You can take these trails up to Granite Basin or over to Thumb Butte. Have fun getting lost. Lots of obstacles and lines people have set up. Rocks to climb. Just good stuff.
Park at the Parking Lot at the Corner of Granite Basin Road and Iron Springs Road. Ride the Road right out of the parking lot. Look for the Emmanuel Pines Sign and turn Left down that Road. It will turn to dirt. There's an area on your right where the single track starts.
http://www.singletracks.com/item.php?c=1&i=5202