In the Belly of the Tongass: Exploring the Depths of El Capitan Cave

Written by Brooke Kubby, 2018 El Capitan Cave Guide

The entrance to El Capitan Cave is somewhat iconic. After the steps pictured here, the cave is totally natural and unaltered (except for the bat gate). Pictured is the 2018 Cave Guide, Brooke Kubby. Photo by Aevind Burgess.

“It’s so… different.”

As we wandered through the halls of El Capitan Cave, I marveled at the rounded boulders, Swiss cheese ceiling, and dripping inner chambers. Many of the corridors reminded me of an alien slot canyon under a dark night sky. I traced the cave’s narrow walls to its roof, which faded into abyssal darkness beyond the reach of my flashlight’s beam. False stars twinkled back at me; diamond-like water droplets glistened on the ceiling.

Without natural or installed lighting, the scene changed constantly as the beams of our headlamps moved up, down, and across one another, highlighting and then plunging into darkness the weird and exotic structures of the cave. The blue-gray mottled limestone, multicolored cobbled floor, and scoured walls were unfamiliar sights for eyes accustomed to the grottos of the American West. As a member of the National Speleological Society, I am an avid caver. But I had never seen a cave quite like this.

Caves often provide a unique habitat for plants and animals. The temperature, shade, and even rock composition can all allow for unique micro conditions. El Capitan Cave is no different. Pictured is a specimen of Green Spleenwort located just outside the entrance. This is a type of fern that prefers calcium-rich rock. The fingertip is included for a sense of scale. Photo by Brooke Kubby.

Prince of Wales Island is home to thousands of limestone and marble caves, each one a unique glimpse into a geologic underworld. The high density of caves is due to a combination of heavy rainfall, faults and fractures within the bedrock, unusually pure limestone, and acidic run-off from northern bogs called muskegs. These factors come together for the perfect cave storm, and the high latitude adds a unique twist to the formation and aesthetic quality of Tongass caves. It was this geological and ecological setting that made El Capitan Cave look so alien to me.

Many of POW’s skyscraper-deep pits, underground rivers, and hidden paleontology sites are located high up in the alpine, accessible only by helicopter. Some pits and caves are a mere dozen feet from major roads, hidden in plain sight behind drooping cedar boughs, prickly Devil’s Club shrubs, and lazily hung green mosses. Others require the help of boats, all terrain vehicles, GPS devices, and technical climbing gear to access. Wherever these grottos may be, the fact is that of the thousands of caves pockmarking this landscape, most are difficult- if not impossible- to reach.

As one ties up their boat and heads up the dock, they will find clear signage directing them to El Capitan Cave. This photo is facing south, across El Capitan Passage towards Kosciusko Island. Photo by Brooke Kubby.

The exception to this rule is El Capitan Cave, which can be easily accessed by boat or car. Named for nearby El Capitan Passage, this underground giant has been visited by humans for at least three thousand years. In the days of old, entering this jewel of the Tongass required zig-zagging several hundred feet up a cliff-like slope. But in 1994, a famous (or should I say infamous?) set of stairs was built, allowing visitors to walk right up.       

Although many people find themselves huffing and puffing, climbing up these stairs is certainly easier than bushwhacking! On the way up, visitors can catch their breath as the Cave Guide points out features of the surrounding forest. Photo by Brooke Kubby.

During the summer months, the US Forest Service offers free tours of the cave. Visiting El Capitan Cave is a unique experience that straddles the line between commercial and wild caving. In the lower 48 states, commercial caves offer such amenities as installed lighting, cement walkways, elevators, and fun gift shops. But El Capitan Cave provides none of these services.

Jessica Petty climbing over the entryway boulders. This is a short section, and is the most difficult part of the tour. It gets much easier from here on in. Photo by Brooke Kubby.

In keeping with Alaska’s rugged lifestyle is this equally rugged cave. After enduring a 370-step staircase up a mountainside, El Cap visitors are asked to don helmets, headlamps, and warm clothes. The entryway is filled with large boulders. After clambering over these rocky obstacles, traversing the cave becomes much easier. The ceiling opens up, evoking that sense of an indoor canyon. At this point the Forest Service Cave Guide unlocks a somewhat medieval-looking bat gate. Beyond this gate, the floor can be a little tricky to navigate. It is less like a dirt path and more like a cobbled stream bottom.

Prince of Wales Island is home to thousands of pits and caves, but only one bat gate. This gate was installed in the early 1990’s to protect wintering bats from humans. It also protects delicate speleothems (cave deposits or formations), archeology sites, and paleontology sites from vandalism. In addition to providing a safe and educational experience for the public, guided tours past this gate help to protect the cave itself. Photo by Brooke Kubby.

Jessica Petty, a POW local, walking through El Capitan Cave. This portion of the cave is outside the bat gate, and is accessible without a guide or reservation. It is the easiest walking portion of any part of the cave. Photo by Brooke Kubby.

As one pushes further into the bowels of the cave, the temperature steadily falls towards 40˚F (4.5 degrees Celsius). Sounds of dripping intensify. Ocean breezes are lost to damp, humid air; smells of the forest forgotten amid the scent of earth and rock. Sunlight fades into everlasting darkness; dappled Devil’s Club shade replaced by beams from battery-powered lights. The fleeting and transient weather of the outside world shifts into the ancient sameness of the subterranean.

The cold quietness is disturbed only by the voices of visitors; the eternal blackness broken only by our electrically powered lights. One often feels a sense of primal uneasiness as their breath floats past the beam of a headlamp. In a modern world tailored to our human needs, we find in this Alaskan cave a place truly not meant for us. It is too cold, wet, and dark for us to stay. There is no food to feed our hungry bellies, no light for our curious eyes, and no fuel for friendly campfires. We are destined to be eternal wanderers; perpetual visitors to these grand limestone halls. El Capitan Cave exists on a timescale far greater than that of its human visitors. It does not belong to us- it belongs to the ages. It is shaped by the melting of glaciers, the rise and fall of the sea, centuries of ceaseless dripping, and floods both ancient and new. 

Prince of Wales is big for an island, exotic for the United States, strangely dreamy… and yet somehow familiar. El Capitan Cave is perfectly at home amongst dancing muskeg hemlocks, prancing Sitka black-tailed deer, and bears that move like living shadows. The sculpted hallways of this blueish-gray cave tell stories older than history itself. They are tales of ancient reefs, tortured rock, great floods, pre-historic creatures, and torch-bearing ancestors. If you find yourself exploring Prince of Wales Island, be sure to enter its underworld. The strange, tall, and dripping passages of El Capitan Cave await the adventurous soul.        

Aevind Burgess sitting on El Cap’s cobbled floor, surveying a small pool of water. Although the cave continues for hundreds of feet past this location, the public tour ends here. Photo by Brooke Kubby.

Brooke Kubby worked as a Cave Guide for the Tongass National Forest. She has a B.S. in Geological Sciences from Arizona State University, and is a member of the National Speleological Society. For inquiries, she can be reached at

Cave tour info by VisitPOW staff


Call at least two days in advance to set up your free tour. (907)828-3304

Parties of up to 6 people. No pets. No children under 7 years of age. No babies in carriers or backpacks.

Dates and days of the week vary from year to year. Call (907)828-3304 in advance. Normal operating months are from May to September.

There are three tours in a day (but not every day of the week) at 9a.m., noon, 2:30p.m. The tour takes approximately 2 hours.

Getting there:

El Capitan Cave is located on the Forest Service Road 20 and is an approximately two hour drive from Craig or Thorne Bay. There is good signage four miles prior to the turnoff and then at the turnoff to direct you. Turn onto FSR 15 and the parking lot for the cave is at 1.6 mile.

Latitude 56.171917

Longitude -133.317778

Leave extra time in your day to stop at Beaver Falls Karst Trail.

Boaters and float plane pilots will find the dock in the northern portion of El Capitan Passage, slightly to the west of the north-south stretch of the passage.

Be prepared:

Wear layers. You might get warm while walking up the steps, and it is going to be chilly (40 degrees), damp, and possibly muddy in the cave. Take a daypack with your extra layers of clothing. A waterproof layer is a good idea.

The trail length is 1100 feet, including 370 stairs, and there is a 250 foot elevation gain. The tour goes 500 feet into the cave. Good, sturdy footwear is important.

Bring a flashlight or two with extra batteries. The Forest Service will provide helmets.

It’s worth it! Go ahead - you’ll love it.

More information:

US Forest Service El Cap Cave Interpretive Site informational page

Beaver Falls Karst Trail

Beaver Falls Karst Trail Interpretive sign Prince of Wales Island POW Southeast Alaska
Boardwalk at Beaver Falls Karst Trail in large timber on Prince of Wales Island POW Southeast Alaska

How does an easy one-mile walk sound? And how about if it’s a boardwalk trail through lovely muskegs and big timber? “Oh,” you say, “throw in some crazy holes in the ground and a waterfall and I’ll do it!”

Wow, do we have the right trail for you!

The Beaver Falls Karst Trail is a great outing, and it even has interpretive signs for your self-guided nature and geology enrichment. The boardwalk itself is wide enough to be accessible, and has pullouts every 300 feet or so. It’s a nice trail.

But let’s get you there first.

Drive north past the Whale Pass cutoff on Forest Road 2000 (the locals call it the 20 road) to milepost 100.5. The large parking lot is on your right. There’s an outhouse and some great signage there, so you’ll know that you’re in the right place.

The trail is at a slightly higher elevation so it might be a few degrees cooler. Bring along an extra layer of clothing just in case.

The first part of the trail goes through a type of Alaskan bog called muskeg.

Beaver Falls Karst Trail muskeg Prince of Wales Island POW Southeast Alaska

Depending on the time of year the muskeg may be tan and rust tones, or green with dashes of cheerful pink and white wildflowers. The coniferous trees in the area stay green throughout the year.

There are delightful natural bonsai trees in muskegs. These small, contorted pines are stunted by the acidic soil conditions and it can take them several hundred years to get just three feet tall!

Beaver Falls Karst Trail muskeg in summer on Prince of Wales Island POW Southeast Alaska

That acidic soil has made the limestone bedrock very interesting. Acidic water seeps down and dissolves the limestone, creating caves, sinkholes, arches, and other karst formations. The trail skirts around some of these impressive formations, and there are railings. I just mention that because the railing made me feel a lot better while peering into an awesome, rugged, vertical, rock sinkhole.

There’s a loop in the trail and an overlook by Beaver Falls. The waterfall varies greatly depending on how much rain there has been. It tumbles down the rocks, makes a turn, and then disappears into a cave!

Beaver Falls Karst Trail overlook on Prince of Wales Island POW in Southeast Alaska

Whether you are making Beaver Falls a destination or a stop along the way, it is well worth your time. Enjoy!