Ten feet beneath the giant Sitka spruce and fierce winds of Alaska’s Tongass National Forest, a dry, narrow passage opens into what may as well be a different planet. Inside this cave, one of hundreds in the region, the glow from our carbide lights illuminates scalloped walls of a meringue-like crystalline mineral that drips into delicate stalactites. The air is cold, silent and still as an ancient tomb.

“This is our last frontier. The deep sea and these caves up here are the only unexplored places left,” says Pete Smith, caver and cofounder of the Tongass Cave Project, an affiliate of the National Speleological Society that is working to inventory and protect caves. “You can climb a cliff that no one’s been on before, but at least you can see where you’re going. When you enter a cave, you don’t know what you’re going to find. The smallest passage could lead to a 500-foot room.”

Created hundreds of thousands of years ago by rainwater that eroded porous limestone bedrock, caves such as this one, underground rivers and deep pits speckle the 16.9-million-acre Tongass National Forest of southeast Alaska. During the past thirteen years, the Tongass Cave Project and the U.S. Forest Service have discovered nearly 600 caves in the area. They estimate there could be 600 more, making this one of the best cave landscapes—known as karst—in the world. Unaffected by development, these caves have revealed 41,600-year-old bear bones, 10,000-year-old human bones and the skeletal remains of thousands of birds, mammals and fish from before, during and after the Ice Age. Such findings have led paleontologists and archeologists to reconsider theories of human migration into North America.

Yet these caves are threatened, says the Tongass Cave Project and Alaska conservation groups. The porous bedrock that produces these caves also produces acres of well-drained soil, creating some of the largest trees in the world—many with ten-foot diameters. When the trees are clear-cut, the forest floor erodes and debris and water can infiltrate the caves, destroying artifacts, stalactites and the fragile structure of these ancient domains. At last count, 39 percent of commercial forest land in the Tongass has already been logged.

Now the cavers fear a new onslaught. In December 2003, President Bush revoked the Roadless Rule in the Tongass National Forest, a regulation created by the Clinton administration that would have prevented any new logging and road building in large tracts of intact forest. Now fifty new timber sales in roadless areas and hundreds of miles of new roads are slated for the next ten years. That’s good news for the timber industry and the locals it employs, but much of that work could take place above undiscovered caves.

In July 2004, the Bush administration introduced a proposal allowing governors to petition the secretary of agriculture to log currently unroaded land. The rule, if finalized, will allow Alaska Governor Frank Murkowski to request that the Forest Service allow logging on an additional 7 million acres of the Tongass. If the agency denies his request, the state could sue.

“[This] throws public participation, sound science and agency expertise out the window. It totally politicizes forest management,” says Aurah Landau of the Southeast Alaska Conservation Council. “The cave systems on the Tongass and their associated forests are an international scientific and recreation treasure, much of which has never been fully explored. This resource is too rare to be logged any more.”

It’s not that simple, says Forest Service geologist Jim Baichtal. He says that not all karst is created equal, and that some already has been damaged by glaciation and is not worth keeping. Also, he adds, the agency has to balance multiple uses of the forest. The federal government owns 99 percent of southeast Alaska and the pressure to provide local jobs is not lost on the Forest Service, especially when global timber prices already are bringing down job numbers. In the past decade, the number of jobs on the Tongass has plunged from 6,200 to 1,100.

“Every single thing we do affects these local communities,” says Scott Fitzwilliams, an agency staff officer for the Tongass. “We have to talk to people whose kids are impacted when they get laid off.”

Despite such economic pressure, Baichtal says the Forest Service strives to protect caves and karstlands. It already has forbidden logging on 53 percent of all karstlands, and Baichtal wants to designate certain areas as “high vulnerability” and place them off-limits from any future timber sale. He also has built a boardwalk trail to showcase karst caves and other features in order to build public support for preserving the resource. Within the timber-friendly politics of Alaska, the Forest Service is doing a good job of protecting karst, says William Jones, director of the Karst Waters Institute in Charlestown, West Virginia. Even so, he adds, “under the present administration they are probably going to cater to industrial interests.”

For the cavers, that political probability means the Forest Service shouldn’t be trusted to protect these precious and rare formations. Instead, they are working to draft a wilderness proposal that would protect Tongass caves and karst forever.

“We’re looking to the future, 300 years from now,” says Kevin Allred of the Tongass Cave Project. “These caves are absolutely enchanting. We want to keep [them] from being impacted again.”