The state park service and various guidebooks about the region list this trail as being one-way-only because of the steep, challenging Diablo Drop Off located near Fish Creek. Although it does not look particularly difficult as you stand at the top and look down, the loose sand makes it difficult to impossible for a vehicle to return up the drop-off. The trail leaves the easier route along Vallecito Wash 1.1 miles west of the intersection with Canyon sin Nombre. It travels up Arroyo Seco del Diablo, a side wash of Vallecito Canyon. For most of the way it twists within this sandstone canyon, traveling in the sandy wash. The loose and fragile walls of the canyon mean that rock and sand falls are common, and you are likely to have to climb over fallen debris. On windy days, dust and sand pour off the canyon walls like miniature waterfalls. Special Attractions: Challenging Diablo Drop Off; Twisting canyon of Arroyo Seco del Diablo through the Carrizo Badlands. High-clearance 4WDs are required. This trail has either a rough, rutted surface, rocks up to 9 inches, mud and deep sand that may be impassable for inexperienced drivers, or stream crossings up to 18 inches deep. Certain sections may be steep enough to cause traction problems, and you may encounter very narrow shelf roads with steep drop-offs and tight clearance between rocks or trees.