Potomac Speleological Club

Sinnett-Thorn Cave Conservancy

About Sinnett-Thorn

The Sinnett-Thorn Mountain Cave System is a complex cave system stretching underneath Thorn Mountain in Pendleton County, WV.

Sinnett-Thorn Mountain Cave System is designated as a National Natural Landmark with the US National Parks Service. The caves are an important habitat for bats and access is strictly managed by the Sinnett-Thorn Cave Conservancy (STCC). The caves reside on private property and the entrances are protected by gates. The property is posted against trespassing. You are not allowed to enter the property unless given written permission from STCC.

To access Sinnett-Thorn caves, use the information and resources on this page to learn how to contact STCC and request access.


Due to White Nose Syndrome caving trips are restricted. As of 1/24/2023 cavers will be able to access the caves for 2 weeks in the spring of 2023. Dates are yet to be determined but will be posted here as soon as we find out. Access dates are dependant on the weather which affects when bats come out of hibernation and before the cave is used as a nursery. We need to try to hit that period in between.

If the West Virginia Department of Natural Resources bat counts show a decrease in populations, access to the cave will be curtailed or eliminated. It’s up to us cavers to keep the numbers as high as possible. Go here to learn about mitigating disturbance to hibernating bats.