Geology of Shenandoah National Park

Close your eyes for a moment, and just imagine what the Blue Ridge Mountains would look like if they were as high as the Himalayas or the Rocky Mountains. Well, once upon a time that could well have been the case, because Geologists believe that the mountains which are part of the Shenandoah National Park are some of the oldest mountains in the world, or at least a part of that elite group, which were once much higher before being eroded and worn down to 4,049 feet, the highest peak in the park these days.

Some of the rocks in the park were formed not just millions, but maybe 1.2 billion years ago, that’s pretty old even for a rock. These are the granite rocks which are evident at Mary’s Rock Tunnel and Old Rag Mountain. Other common types of rock in the park are basalts which were created from lava flows, (these are pretty young rocks, only around 570 million years old) and sandstone and other sedimentary rocks which are even younger.

You can see some great examples of the rock formations as you drive along Skyline Drive, in particularly, check out the overlooks at;

• mile 32.4 – Mary’s Rock Tunnel (the granite)
• mile 44.4 – Crescent Rock
• mile 49 – Franklins Cliff