When Alaska was admitted into the Union in 1959 it was officially nicknamed ‘The Last Frontier.’ It’s as suitable a label now as it was then: the majority of the state’s land — an area approximately 2.5 times the size of Texas — remains wilderness. Some peaks here have never recorded a single human ascent. The sweeping, mountainous panorama suggests an unshakable permanence. In actuality, though, much of this landscape is shifting at an alarming pace.

Atop Mt. Hunter in Denali National Park, summer temperatures are as much as 3 degrees warmer than they were a century ago. As a result, immense flows of ice are disappearing sixty times faster than they were at the end of the 19th century. What might have taken millennia to recede is now gone in a decade. In the halls of power, a great debate rages on as to the underlying causes. But in this part of the world, it matters not. The most hike-able glaciers in Alaska are undoubtedly going away. If you want to explore them before they’re gone for good, don’t wait too long. Here’s what to see now, and how.

Hatcher Pass, Alaska
Credit: Doug Lindstrand/Design Pics/Getty Images

“We’re coming into our 16th summer guiding glacier hikes,” says Heather Szundy, owner and CFO of Ascending Path Guide Service. “In this time frame we have had to abandon 3 separate glaciers, due to access melting. We are now on our 4th — the Spencer Glacier.”

Isolating access points is the most significant safety consideration when hiking these massive fields of ice. Along the periphery of the glacier is a zone in constant flux, calving chunks the size of small cars can cause injury and death. To minimize the threat, guides find places where frozen edges slope most gently to meet the underlying moraine. “In 2012, we lost walk-on access to Spencer on the north side,” Szundy recalls. “We had to shift to kayaking across a lake to access it from the south side of the glacier.”

It wasn’t all bad. Nowadays adventurers paddle past a mesmerizing labyrinth of turquoise-hued icebergs as 3,500-foot tall Spencer rises in the distance. Its serrated terrain slowly reveals itself in sharpening relief. But for how long?

Matanuska Glacier, Alaska
Credit: Noppawat Tom Charoensinphon/Getty Images

“This current method for access is deteriorating fast,” warns Szundy. “Last year we had a week where we lost walk-on access all together.” This season, Ascending Path’s day adventure on Spencer Glacier will set you back $389. Yet it’s becoming increasingly expensive to enjoy experiences such as these.

The more machinery required, of course, the more you can expect to pay. “For the last 15 years, we have occasionally used helicopters to access and provide glacier hikes and ice climbing for visitors to Alaska,” says Szundy. “But it is becoming apparent that in the future, to get onto a glacier in south-central Alaska — and worldwide — will require a helicopter.”

Helicopter Glacier, Knik River Lodge
Credit: Peter Schadee/Courtesy of Knik River Lodge

Peter Schadee is prepared for this eventuality. He runs Anchorage Helicopter Tours out of the backyard of the charming new Knik River Lodge. For $359 per person, he’ll take you on a 60-minute adventure, where you’ll land atop Knik Glacier, one of the largest ice fields in this part of the state — also one of the fastest shrinking. “In the 15 years that I have been flying in that area I’ve seen the glacier recede at least a half mile, and the thickness at the edges go from 200 feet to 75 feet,” he observes.

Knik River Lodge, Alaska
Credit: Lars Larson/Courtesy of Knik River Lodge

Follow this widened valley south along the Knik River and you’ll land on the Colony glacier, which, as recently as 2015, used to feed directly into a silt-strewn pool of thawed ice — Lake George. Not anymore. “Now we see land appearing to form under the glacier,” adds Schadee. “Every year you see a difference, and I would not be surprised if in 10 years, this glacier no longer calves its icebergs into the lake.”

For now, the views are stunning. And there’s nothing quite like landing on top of a glacier. Though, if you’re going to fly to one, you might as well stay for the night. Sheldon Chalet affords this possibility with a level of luxury befitting its lofty perch — as long as you can afford $2,300 per night. The lodge rests on a nunatak in a bowl of compacted snow a mile deep, under the shadow of Denali.

Sheldon Chalet, Alaska
Credit: Chris Burkhard/Courtesy of Sheldon Chalet

Owner Robert Sheldon — whose family has owned the pristine lot since before Alaska was even a state — has been allocating resources to welcome and assist climatologists. “We have quite a bit of land up there,” explains owner Robert Sheldon. “It’s only five acres, but that’s a surprising amount of space in the middle of [a national park]. We’re segregating off some property where guests can’t go, to [permanently] house scientific equipment. We want a better perspective of what’s going on up here, decade after decade.”

Not so long ago, hiking onto a glacier cost nothing at all. In Kenai Fjords National Park, Exit Glacier was a popular attraction for just this reason. A moderate trail, less than a mile from the parking area, once provided free access to a walk-on field of dense, bluish-white ice. Rapid retreat up the hillside dragged the glacier permanently beyond the reach of the viewpoint in 2010. It is still a stark site. But its poignancy is punctuated by signposts along the edge of the trail: a series of years tracing the terminus’ pullback up the valley floor throughout the past century.

Kenai Fjords National Park, Exit Glacier
Credit: Michael Jones/Getty Images

The only other option available today is off the Glenn Highway, about 100 miles northeast of Anchorage. The 27-mile long Matanuska Glacier is the largest in the country accessible by car. Glacier Park is a small campground here providing access to the ice by way of a 20-minute hike. The entry fee is $30 per day.

For years, this was the ideal way to explore this unique landscape. There were few complaints. “High end tourism didn’t really exist in Alaska,” according to Sheldon. But it’s rapidly becoming the only way to see glacial terrain. Most tourists sightsee by driving, which limits them to the 14% of state accessible by road. “The glaciers that are easily approachable by the highway system are vanishing.”

To those willing to camp overnight, Sheldon recommends a two-day hike through Hatcher Pass, just south of his hometown of Talkeetna. “It’s about a 70-minute drive north of Anchorage. For seeing a glacier from an on-foot perspective, that’s pretty much it in this part of Alaska,” he says. “Things have really changed that much.”