The Robledo Mountains Off-Highway Vehicle (OHV) Trail System is a network of trails, including both extreme OHV and mountain bike trails, in the southern Robledo Mountains. Trails within the System lie within both the Prehistoric Trackways National Monument and the Organ Mountains-Desert Peaks National Monument. The trails are dominated by enormous rocks, making the terrain extraordinarily challenging for riders. The extreme OHV trails require specialized vehicles, with locking differentials, winches, and expert drivers. Vehicle damage is not uncommon on these very difficult OHV trails. The area also includes the "SST" mountain bike trail, which is open only to non-motorized uses. It also is an extremely technical trail -- traversing challenging rocky terrain, steep canyons, and mountain-top ridges -- and requires expert riding skills. The area is open year-round with no fees.