About 15 miles of very fast, hard packed, rolling single-track. Four different loops connected by the Frontier Trail. Except for the Tower Climb, which contains 8 uphill switchbacks, nothing technical. Great place to ride year round but a little hot in the summer. Huge lake recreation area so bring the family along while you ride. Maps, videos and photos at my site: http://arnica.csustan.edu/mtbike
Glory Hole recreation area is on New Melones Reservoir off of Hwy 49, about 4 miles south of Angels Camp, which is about 60 miles east of Modesto.
http://www.singletracks.com/item.php?c=1&i=77