Looking Glass Rock and the Age of the Blue Ridge

The bare granite dome rising from the Pisgah National Forest floor is called Looking Glass Rock because in winter, when the rock face is wet and iced over, it catches the light from certain angles and throws it back like a mirror. The effect is local, seasonal, and real. The name is approximately two hundred years old.

The rock itself is considerably older. The granite that forms Looking Glass is part of the basement rock of the Blue Ridge, crystallized approximately three hundred million years ago from magma that never reached the surface. What you are looking at is the interior of a mountain range, exposed by the slow removal of everything that once covered it. The southern Appalachians have been eroding since they formed. They were once higher than the Himalayas. What remains is the bottom.

The Appalachians are among the oldest mountain systems on Earth, formed during the collision of the ancient continents roughly four hundred eighty million years ago, hundreds of millions of years before the Atlantic Ocean opened. The Himalayas, by comparison, are geological children, raised when India collided with Asia approximately fifty million years ago. The Blue Ridge you are driving through has been here, in some form, for roughly ten times as long.

A few miles from Looking Glass Rock, the Forest Service operates Sliding Rock, a natural granite water slide where a stream runs down a forty-foot sloped rock face into a clear pool. The Forest Service maintains a lifeguard station there in summer. The slide operates on the same ancient stone. The lifeguard is a recent addition.