Stillwater Range front and Big Box Canyon.

Looking west from Nevada State Route 121 in Dixie Valley, central Nevada. The prominent break in slope running roughly horizontally across the middle of the picture marks the trace of the range-front boundary fault, where the Stillwater Range is being uplifted with respect to Dixie Valley. The slope above that break is the fault-plane surface, little modified by erosion. Big Box Canyon (outlined) is a slot canyon that's incised into the range front. The downcutting by the stream is more or less keeping pace with the uplift, but the canyon remains narrow because the erosion is (geologically!) happening so quickly. The tapering downward canyon cross-section ("wineglass") is characteristic of streams cutting across active high-angle faults.

Faulting here is ongoing: a huge earthquake in December 1954 (~Richter 7.4) left a ~15 ft (~ 4 m) scarp along much of the range front. It's barely visible here, but is much more prominent elsewhere. This area lies in the Central Nevada Seismic Belt, a north-south trending zone that's been the site of other large historical earthquakes.