All of the rocks in the gorge are sedimentary. That means they must have been deposited at one time and then later eroded. At various times in the geologic past, the Appalachian Mountains reached much higher elevations than they do today. Any topographic high will erode down over time, and as the ancient Appalachians were being eroded, some of that sediment found its way to what is now the Red River Gorge. The sandstone that caps most of the hills in the gorge area was deposited in river deltas about 320 million years ago, which was long before dinosaurs ever appeared on the planet. This sandstone is very important here because it is a lot stronger than any other rocks in the area. The two other rock types in the gorge, shale and limestone, can be easily eroded.
When sedimentary layers are deposited they are flat-lying, but they can be deformed during future geologic events. The features at the Gorge were greatly influenced by the Cincinnati Arch, a broad large-scale anticline that spans the central parts of Kentucky and Ohio (an anticline is an upward bending of rock layers). It formed approximately 40 million years ago, during the Pennsylvanian time period. Over time, the peak of the anticline began to erode. Once the sandstone layer was breached in the center, the underlying shale and limestone were quickly eroded away, producing a large valley. The Red River Gorge is on the edge of this valley, where the sandstone is still present on the top of some hills.
The features you will see today were formed by the powerful forces of erosion. Keep in mind that erosion is an ongoing process. As you look at different features today, think about how they will change over time. What will eventually happen to them?