Devil's Den

The sight of huge rock formations once thought to be haunted by the residents of Gettysburg. 

The open fields of Gettysburg, Pennsylvania were once the site of the Battle of Gettysburg, a famous Civil War battle. Year-round, this town is visited by tourists seeking out a closer look into the country’s past. This however, is not the only key point that this area is known for. The battlefields are also known for their unique topography and geological features. Such features include the high point of Big Round Top and the immense boulders of Devil’s Den towering over the rest of the landscapes. 

The area came to be the way it is today over the course of millions of years. 240 million years ago the Gettysburg Basin was formed through the shifting of two tectonic plates away from one another. This turned into the Gettysburg Formation 180 million years ago when   mudstone, silt, shale, sandstone, and limestone were all deposited into the huge basin and compressed under high pressure. Years after, Devil’s Den was formed when huge sills and dykes reached the surface, through the Gettysburg Formation. These formations were enormous as the sill that altered the landscape of the land was around 2,000 feet thick and the two dykes that broke through the surface were over 50 feet each.

As people began to colonize the United States, the town of Gettysburg came to be. This town and the nearby fields would one day become the site of the Civil War battle, The Battle of Gettysburg. Diabase is very dense and resistant to weathering, which explains why most of the exposed bedrock in the area is diabase. All other formations that layered over the Gettysburg Formation have likely eroded away almost entirely. During the Battle of Gettysburg, it was noted that deep holes could not be dug into the earth in many of places because of this, so boulders were used for cover instead.

These rock formations are a sight to behold and even more fun to explore. There are a wide variety of things to do as visitors can explore the fields near by, hike up the mountain, or climb into the small caves that exist inside of the formations. Some spaces are big enough to stand in while others are small enough to crawl through.