Cavern Lake Cave

Cavern Lake Cave Trail and Viewing Deck

Useful Information

Location: Tongass National Forest, Prince of Wales Island, southeast Alaska.
State highway 929 to Control Lake Junction, 925 for 15 miles, becomes Forest Road 2000. After Beaver Falls turn right on Loop Rd (27 Rd) 5 km. Signposted, parking lot at trailhead.
(56.157091, -133.172602)
Open: no restrictions.
Fee: free.
Classification: SpeleologyKarst cave
Light: none
Guided tours: self guided
Photography: allowed
Accessibility: no
Bibliography: Kevin Allred (1989): Cavern Lake Cave, Techical Preliminary Report #12, The Alaskan Caver, Volume 9, Number 5, November 1989, pp 1-6.. pdf
Address: Tongass National Forest, Federal Building, 648 Mission Street, Ketchikan, AK 99901-6591, Tel: +1-907-225-3101, Fax: +1-907-228-6215. E-mail: contact
USDA Forest Service, Thorne Bay Ranger District, 1312 Federal Way, PO Box 19001, Thorne Bay, AK 99919-0001, Tel: +1-907-828-3304, Fax: +1-907-828-3309.
District Ranger: Mark Pentecost, Tel: +1-907-826-3271. E-mail:
Deputy Ranger: Delilah Bingham, Tel: +1-907-828-3210. E-mail:
As far as we know this information was accurate when it was published (see years in brackets), but may have changed since then.
Please check rates and details directly with the companies in question if you need more recent info.


1991 Tongass Cave Project (TCP) founded.


The Cavern Lake Cave Trail is a short trail to Cavern Lake Cave, about 70 m long. It ends at a viewing deck providing a view into the mouth of Cavern Lake Cave. There is a stream coming from the cave mouth, which makes it an impressive sight. It is not possible to enter the cave as it an active river cave, and rather dangerous. It is necessary to wade through cold water and there is the danger of flooding, so cave visits are not advisable.

The island consists of crystalline rocks marble or limestone patches. The karst is a typical contact karst, where water flows on the surface until it reaches the soluble rock, then vanishes underground, just to reappear at the border to the insoluble rock and again flow on the surface. The water of Cavern Lake Cave originates from Cavern Lake on the hillside above, which is a Karstkarst lake and has no outflow on the surface. The water of the lake drains through this cave.