a series of ripple-like folds in these rocks, not all that unlike what occurs if you push together two sides of a bedsheet. The alternating series of parallel ridges and valleys seen directly to the south of High Knob, in fact, are the result of this "fold belt" in our portion of the Appalachians. Here in the vicinity of Powell Valley, sedimentary rocks were folded upward into a dome-shaped fold called an anticline.

But wait: we're talking about a valley here - how could it be formed from rocks that were folded upward?  In Powell Valley's case, the sedimentary rocks that were pushed upward eroded more quickly when exposed to wind and water than those on either side of the fold. Erosion - particularly erosion caused by water on porous limestone - dislodged surface materials and continued until a steep-sided valley was formed. Due to this erosion, a karst environment—or limestone-dominated terrain—is exposed on the floor of Powell Valley today, while the ridges hemming it in on either side are composed of resistant sandstone. You can most easily see this eroded heart of High Knob today from the scenic overlook on US Highway 23 between Big Stone Gap and Norton - a road you may have driven on your way up to the Knob.