This trail teeters on the edge of being buggy territory. Very skilled drivers in heavily modified full-size rigs have successfully negotiated it, but few of them escaped body damage. Many rigs have had big fails here. This trail begins and ends at the bottom of the rock formations just to the south of Sand Hollow State Park. While not as high rated as Arrowhead Canyon in the next canyon to the east, it still has plenty of adrenaline factor for buggies and heavily modified full body rigs.
Pause to take in views of Sand Hollow Reservoir immediately to the south with Zion Park in the distance. The usually snow-capped Pine Valley Mountains are to the west, and Hurricane Cliffs are to the east.
Slickrock canyons, wedges, and ledges. Some sand hills.
Chain reaction begins in a sandy wash by Sand Hollow Reservoir. The first obstacle is one gigantic waterfall. This obstacle is buggy only. The waterfall is easily bypassed by entering into the wash a little further up. Chain Reaction consists of Lower Chain and Upper Chain. Lower chain follows this wash. It is full of obstacles that can get ugly real fast if you are not careful. The wash narrows into a tricky series of falls and around a bend that requires maneuvering your rig by a massive boulder. Then it opens up and you begin making your way out of the wash. To reach Upper Chain, the driver must climb a very slick and vertical hill. At the top, Upper Chain begins, leading you along the ridge above the wash. Upper chain presents just as many intimidating challenges to both the rig and its driver. You will almost always receive some "love bites" from the rocks. Rigs need to be, at a minimum, locked front and rear with at least 35" tires. Chain Reaction has an extremely high possibility of body damage and/or mechanical breakdown.