Here, the topographic expression of structural features is spectacular. The north-south trending Kings Crown Peak-Apache Leap escarpment divides the area into two major topographic units. East of the escarpment is an upland capped by welded dacitic tuff. West of the escarpment, erosion, acting upon faulted basement blocks and thick accumulations of eruptive rocks, has produced a rough terrain at lower elevations. The mining community of Superior is situated in a fault-formed basin in the central part of the area. Rugged landscape southwest of Superior is commanded by Picket Post Mountain, which is an eroded volcanic vent; the remnant of a once extensive volcanic pile.