Steve Lewis and his friends love naming caves: Slug’s Plunge, Toad’s Plunge, Die Hardyman Hole, Blowing in the Wind, and Two Deer Pit.  Macho Peak-A-Boo, a challenging vertical-descent cave complete with skylight.  Enigma Cave, and its diminutive neighbor, Slightly Enigmatic.
 
Many spelunkers would do just about anything to have the honor of naming even one cave, but for seasoned Alaskan cavers like Steve, it’s a fairly regular event.  Many of the islands in Southeast Alaska are richly endowed with karst, a landform created when rain and snowmelt dissolve limestone to form a labyrinth of caves and underground streams.  As a founding member of the Tongass Cave Project, Steve has spent much of the last decade dropping into 500-foot pits, climbing 30-foot walls, swimming underground pools, and squeezing through wormholes, all in pitch darkness and often in uncharted territory. 

There is much uncharted territory on Dall Island, a rugged, wave-pounded island in the southernmost reaches of the Tongass.  Steve loves the island’s weathered rocks and grassy hills because they have an “out-there feeling” unique to remote islands that, like Dall, face the open ocean.  “There aren’t any giant mountains or huge cliffs or the biggest trees on the Tongass,” he says, “but it feels wild.”

It is also peppered with caves.  “The density of sinkholes on parts of Dall is some of the best in the country,” Steve says.  Even on a place like Dall, which, geologically speaking, might as well be a giant slab of Swiss cheese, finding caves can be a tricky business.  Years of experience have taught Steve some of the nuanced differences in terrain and undergrowth that can signal the presence of caves, but, he says, “You have to develop an eye for each island.”  On Dall, Steve and his companions study aerial photos and geological maps, then walk the ground in search of pits, sinkholes, and grikes (fissures in limestone).

In the course of exploring and charting caves in Southeast Alaska, Steve and other Tongass Cave Project members have discovered human and animal remains as much as 40,000 years old.  Many of the caves they have explored contain the sleeping holes-turned-gravesites of bears, foxes, and otters that curled up for winter before the rise of human civilization.  In 1996, paleontologist Tim Heaton was about to wrap up an excavation of On Your Knees Cave when, filling the last bag of sediment, he found human bones that were later radiocarbon dated as 9,800 years old. 

Steve and other Tongass Cave Project members believe that Southeast Alaska’s karst is both unique and undervalued.  Bones dissolve in the acidic surface soil of the Tongass, but basic limestone can leave them untouched for millennia, making caves the only places in the region that preserve these remains well.  As such, they are “the only places on the Tongass where we are going to get a good window into our history in terms of human migration into North America, as well as the way plants and animals moved into Southeast Alaska as the glaciers receded,” Steve says. 

Alaskan caves are as fragile as they are valuable.  Because it is so porous, karst makes for well-drained soil that produces magnificent stands of ancient spruce that are coveted by the timber industry.  Unfortunately, logging projects often devastate karst systems.  Cave entrances are blocked, slash and sedimentation plug up caves and the animal remains within, and redirected water dissolves ancient limestone formations.  In the last decade, Tongass Cave Project members have worked with the Forest Service, television crews, writers, and conservation groups to advocate for protection of Tongass caves.

But the group has always been about more than saving karst.  It’s about the thrill of adventure – a thrill that, Steve’s friends say, has prompted him to jump into icy underground pools without remembering to zip up his drysuit.

And as much as anything else, it’s about being on the cutting edge.  As Steve says, “Think about it: discovering a hundred feet of virgin passage in a cave.  That’s something that most people would kill to do.  It’s a privilege to be a part of that.”