Tongass National Forest


Few places in the world have karst terrain developed to the extent that it has in southeast Alaska. Karst is topography characterized by caves, sinkholes, and underground streams. About 700 square miles of karst topography exists on Prince of Wales Island. These have formed from limestone and marble bedrock dissolved by our abundant rainfall. The karst ecosystem is one of the most productive ecosystems for both plant and animal communities in southeast Alaska.

Caves are valuable for a variety of reasons, from recreational to scientific. The features and contents of caves are extremely fragile. Caves are, essentially, nonrenewable resources.

Cave exploration and development is only just beginning. Currently, the Thorne Bay Ranger District has developed the El Capitan Cave Trail (#775) and the Cavern Lake Cave Trail/Viewing Deck (#777).

775 El Capitan Cave Access Trail
Trail is approximately 1,300 feet in length, and climbs about 300 feet from the parking lot to the cave entrance. Considered to be a "more difficult" hiking opportunity, and features a combination of tread types which include gravel, boardwalk, wooden stairways, and natural tread. A gate has been installed inside the cave about 150 feet from the mouth to protect the cave resource and ensure the safety of visitors. Even the first 150 feet of the cave contains uneven footing and other hazards. Proceed with caution! The Thorne Bay District will also be conducting guided walks into the cave throughout the summer. Please contact the Thorne Bay District for more information on accessing this cave.

777 Cavern Lake Cave Trail and Viewing Deck
A short trail approximately 250 feet in length. Access is off road #27. The trail leads to a viewing deck which provides excellent views of the mouth of Cavern Lake Cave and the stream gushing from the cavern. Don't go in: the cavern is considered very hazardous, with potential for injury or drowning. But you can enjoy the site from outside.


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