Thin Ice

Exploring Mount Hood's Glacier Caves

By Amelia Templeton and Ed Jahn

Thin Ice

Exploring Mount Hood's Glacier Caves

By Amelia Templeton and Ed Jahn

On the slopes of Mount Hood, six explorers set off in a line up the Sandy Glacier. Eddy Cartaya pulls ahead of the group, a stony expression on his face.

He’s wearing a white helmet with his name and “Cave Rescue” printed on it. Cartaya is worried because the sun is starting to rise and hit the ice.

His climbing partner Brent McGregor follows at a more reasonable pace. The bearded 60-year-old takes in the morning and smiles.

“One of the best sounds in alpine mountaineering is the sound of crampons and ice axes on good firm snow,” he says.

The Sandy Glacier flows down a steep bowl about two-thirds of the way up Mount Hood’s northwest side. You can see it from Portland, Oregon, a wedge of snow and ice between two broken ridgelines that rise toward Hood’s 11,250-foot peak.

The team isn’t interested in the summit. McGregor and Cartaya are leading their expedition to a gaping hole in the glacier. It’s a moulin: an icy pit that drops like an elevator shaft from the surface of the Sandy Glacier down to the bedrock below.

Like Alice’s rabbit hole, the moulin is a portal to another world. It leads into an ice cave that McGregor discovered underneath the glacier in 2011.

Since then, McGregor and Cartaya have mapped more than a mile of caves and tunnels beneath the Sandy.

The explorers suspect the beautiful formations account for a significant loss of the glacier’s ice, and they have set out to measure how much these openings are increasing in size each year. It’s an unconventional mission. Climate scientists and glaciologists have tracked the melting of more than 200 glaciers around the world, but they’ve almost always gathered their data from the surface. Taking measurements from within a glacier? That’s a new scientific frontier.

In addition to their climbing gear, the team carries survey tools. At the mouth of the moulin, they build anchors in the snow and begin fixing ropes.

“ROCK!” someone calls out.

Everyone wheels around. A rock the size of a baseball rolls down the slope past the group. A harmless event, but a reminder that a rock could easily tumble into the moulin and kill a person standing at the bottom.

McGregor ropes up and walks to the edge of the pit.

“Going down in, it humbles you. You’re like a little ant in there,” he says.

Radio communication is impossible under the ice, so Cartaya strings a Norwegian military phone line, known as a cricket phone for the chirping it makes, down into the moulin. McGregor will let the team know whether the cave is safe to enter.

McGregor begins to descend. In places, melting has exposed boulders that rolled on to the ice hundreds of years ago and were incorporated into the glacier. They perch precariously above his head.

He drops out of sight.

A few minutes later, the phone chirps. The team can barely hear McGregor over the sound of rushing water.

“You can come down. And it’s unfriggin’ believable,” they hear him say. “It’s changed tremendously. You won’t even recognize it.”

“You can come down. And it’s unfriggin’ believable. It’s changed tremendously. You won’t even recognize it.”


A World Beneath The Ice

McGregor and Cartaya have identified three distinct caves in the Sandy Glacier and named them Snow Dragon, Pure Imagination and Frozen Minotaur. The combined 7,000 feet of passages reach like fingers of a hand beneath the ice.

Discovering The Caves

Snow Dragon
First reported sightings in the mid-2000s
Pure Imagination
Discovered by McGregor and Cartaya in 2011
Frozen Minotaur
Discovered in 2011

They may comprise the longest glacial cave system discovered in the U.S. outside of Alaska, according to experts.

One of them is Jason Gulley, a glaciologist at Michigan Technological University.

Gulley says it’s hard to say for sure because few people have the skills - or the inclination - to explore a glacier’s plumbing system. Gulley is one of the few. He crawled deep inside glacial caves in Nepal, Alaska, and Svalbard during his field studies.

  • Thin ice in the caves appears blue-green.
  • The ice inside Snow Dragon is too brittle to climb with traditional ice tools, so Eddy Cartaya uses an aid-climbing technique to search for new passages.
  • The moulin
  • Jed Medin in Pure Imagination Cave, during the 2012 expedition. Pure Imagination extends for a half-mile under the glacier, connecting the Cerberus moulin on the glacier's surface to a lower entrance at the glacier terminus.
  • Barb Williams emerges from Pure Imagination cave after several hours of exploration under the ice. Williams and several other team members are volunteers with Deschutes County Search and rescue.
  • The clear blue ice formed when winter rains pooled on the glacier or filled a crevasse and then re-froze when the temperature dropped.

Inside The Caves

“There’s really only three or four people in the U.S. that are managing glacier cave exploration,” Gulley says. “You have to have all the caving skills to negotiate the caves, but you have to have the mountaineering skills to get there.”

Moulins and caves are normal features in glaciers. They function as the drainage system for these rivers of ice. Normally, conduits form when temperatures rise and melt water flows down through cracks in the ice. They collapse when the melt season ends. It’s an annual cycle.

Large, permanent caves like those on the Sandy only form when a glacier is thin and the weight of the ice no longer squeezes the caves shut, allowing warm air to flow into the glacier.


The Artist And The Ice Climber

McGregor and Cartaya have drawn on years of experience mountaineering and caving to safely explore the caves in the Sandy Glacier.

Their personalities complement each other. McGregor is a free-spirited photographer, mountaineer, and woodworker; Cartaya, 44, is is a Type A law enforcement officer for the U.S. Forest Service and an ice climber with search-and-rescue experience.

Brent McGregor

As a teenager, McGregor bought a canoe and decided to paddle it the length of the Canadian coast to Alaska. Later, he took up logging and woodworking and spent four years hand-building a cabin in Wyoming— and all the furniture inside.

McGregor started mountaineering in his 40s, summiting the Cascade volcanoes from Shasta to Rainier. He once spent a night on Mount Jefferson after breaking a leg on his way down from the summit. He says he struggled to find a caving and mountaineering partner who was as adventuresome as he was.

“Not that I had a death wish, but I was very curious about things out in the natural world and wanted to see what was there,” he says.

Even Cartaya’s closest friends speak about him with a kind of awe. He attended West Point, plays the piano, and spends much of his free time volunteering with Deschutes County Search and Rescue.

Eddy Cartaya

Cartaya moved to Oregon from North Carolina, where he worked for the National Park Service. A skilled rock- and ice-climber, he used to free solo, or climb without safety gear.

Then his climbing partner died in an accident on waterfall ice in 2010.

“It brought the risks more into focus,” Cartaya says. “I used to climb without ropes on ice and rock. Now I’ve stopped doing that.’

A few months later, U.S. Forest Service hired Cartaya as a law enforcement officer and manager for the hundreds of caves in Central Oregon’s Deschutes National Forest.

One of his first jobs in Oregon was a 60-year-old cold case involving rare rock formations that had been stolen from a lava tube. It was McGregor, the head of the local caving association, who brought him the case. Cartaya tracked down the missing lavacicles.

The two clicked immediately and began caving and climbing together. It wasn’t long before McGregor shared with Cartaya his dream of finding a glacier cave.


The Way In

Over the years, McGregor searched 17 glaciers in Oregon without any luck, rappelling into crevasses and marveling at the snow formations inside. Then in 2011 he found a YouTube video of people inside a cave in the Sandy Glacier.

A thick blanket of fog covered the glacier the weekend he and Cartaya went looking for it. The men spent a day searching for the entrance and found nothing. On the second day, McGregor spotted a deep crack in the ice.

“As soon as he shimmied his way through, you could hear whooping and hollering, going crazy in there,” Cartaya says.

The cave on the other side of the crack was large enough to fit an orchestra inside and stretched deep into the glacier. Its white walls were scalloped, as if someone had been sculpting the ice with a giant ice cream scoop. McGregor and Cartaya named it Snow Dragon.

Cartaya had discovered a handful of limestone caves back east. McGregor had helped discover new lava tubes in Oregon.

But they’d never found anything like this before. The cave sucked them in, not only because it of its unique beauty, but because the ice was constantly changing.

“Here’s a place that you don’t just discover once,” Cartaya says. “You can discover it again and again.”

“Here’s a place that you don’t just discover once. You can discover it again and again.”


Cave Fever

The prospect of exploring a passage that no human has ever seen before turns serious cavers a little crazy.

“They’ll quit work, not go home for days, do whatever they need to do to get there, be the first one to experience it, and document it,” Cartaya says.

It’s called cave fever, or just the fever.

McGregor avoids falling boulders while wiggling through a small hole in the ice.

After McGregor and Cartaya saw Snow Dragon, they developed a bad case of the fever. They combed the glacier for more caves. Late in the summer, McGregor wiggled through a small hole in the ice and found a wide passage arched like a railroad tunnel that led him deep inside the glacier. A waterfall forced him to turn around before he reached the end. He named the second cave Pure Imagination.

After that, McGregor and Cartaya discovered the moulin together. They named it Cerberus after the three-headed dog that guards the gates to the underworld of Greek mythology.

They kept exploring through the dead of winter. Cartaya remembers thinking that even a minor injury like a sprained ankle could have left one of them dead from hypothermia.

Eddy Cartaya prepares to enter Snow Dragon during a mid-winter visit to the glacier.

“We didn’t have any communication for help,” he says, “and we’re inside a place that nobody even knows exists.” On a trip in January, they slept inside Snow Dragon to take shelter from a fierce storm.

They found a third cave, named Frozen Minotaur, a maze of unstable tunnels filled with rolling rocks and frigid whitewater. They hauled in scuba gear to explore it. At one point, McGregor’s wetsuit came unzipped and immediately inflated with freezing water “like the Michelin Man,” he says. He thought for a moment his heart had stopped. Cartaya dried him out and warmed him up.

Each return to the changing ice world brought a new rush of adrenaline for Cartaya, a new natural sculpture for McGregor to photograph. But adventure and discovery didn’t satisfy them.

They felt there was more to to be learned from the world they had found. They collected feathers and seeds that dropped out of the ice and watched the rivers inside the glacier change course.

In particular, as they watched the caves grow, they suspected that the openings were causing the glacier to melt and retreat faster.

So last summer, the men organized their first full-scale expedition to formally survey the caves. With the help of dozens of friends from Search and Rescue and the caving community, they mapped and measured more than 7,000 feet of passages underneath the Sandy Glacier.

“I’m hoping it will make people appreciate the value of glacier resources, as they go away,” Cartaya says.


Planning an Expedition


Planning an Expedition

More than anything, McGregor and Cartaya hope that scientists will take an interest in the caves. Last year, they reached out to Andrew Fountain, a glaciologist at Portland State University.

Gunnar Johnson

Fountain sent one of his graduate students, Gunnar Johnson, who studies the water chemistry of glaciers and microbes that live underneath the ice. Johnson said he found a surprisingly diverse population of tiny organisms that survive by essentially digesting the rock underneath the Sandy Glacier.

“If there is life on Mars to be found by this next rover, it’s going to look an awful lot like the things that are living under this glacier right now,” Johnson says.

But Fountain himself was lukewarm on the subject of glacier caves.

“There are some aspects of glacier caves that are interesting. As a main subject of study, not so much,” he said.

Fountain said he’d consider joining the expedition if he could find the time.

McGregor and Cartaya keep their fingers crossed while preparing for their second round of surveys.

When the expedition begins in late July, it takes the group most of a day to hike to the glacier terminus. They follow the Timberline Trail 5 miles to a steep climbers path and then traverse a slope of heather and scree. Their packs are loaded with 80 pounds of gear: ropes, wetsuits, crampons and axes, freeze-dried peas, survey gear, avalanche probes, oatmeal, cocoa and a 45-pound RV battery.

  • McGregor and Cartaya have little funding for their expedition. Friends from search and rescue and caving clubs help the explorers haul gear up the mountain.
  • The volunteer team spends a week camped at 6400 feet on at outcrop of rock at the Sandy Glacier terminus. They’ve named it Kamp Tenacious.
  • A team prepares to climb up the glacier and to scout the entrance to Pure Imagination cave.
  • Rigging a line into Cerebus moulin and Pure Imagination cave.
  • Eddy Cartaya ice climbing. During their week on the glacier, the team surveys the caves and searches for new passages.
  • Barb Williams watches Cartaya climb.
  • McGregor fills up a mug.
  • McGregor’s partner Kara Mickaelson has joined him on many trips to the glacier caves, and serves as the expedition’s cook and camp host.
  • Cartaya maintains radio communication with Portland Mountain Rescue during the expedition.
  • McGregor enjoys the sunset.
  • After midnight the team hikes up the glacier to survey the Cerberus moulin, lighting it up with their headlamps.

Life at 6400 Feet

Photos by Katie Campbell

McGregor and Cartaya give their little circle of tents at the glacier’s terminus an official name: Kamp Tenacious.

Camped out on the snow on the first night, Cartaya and McGregor’s team of volunteers can see the Milky Way and the lights of Portland 60 miles away.

The next morning, Gunnar Johnson, the doctoral student who’s been studying the microbial life in the caves, hikes in to take water samples. He brings good news: He’ll return to collect more samples tomorrow. And Andrew Fountain, the glaciologist, is planning to come with him.


The Snow Dragon

Buoyed by the news, McGregor and Cartaya begin their second year of survey work in Snow Dragon cave. The most dangerous part of Snow Dragon is the entrance. Flakes of ice that weigh more than a ton threaten to pull away from the ceiling. Most members of the team do a little jog to pass through the entrance as quickly as possible.

The glacier is hundreds of years old. Bands of amber in the ice mark each year of snowfall that piled up on top the glacier and compressed into ice over time. In places, layers of perfectly clear ice show where winter rains pooled on the glacier or filled up crevasses and then re-froze when the temperature dropped.

The survey in Snow Dragon goes quickly at first. The cavers make their way from the entrance deep into the cave. It’s pitch black. Blocks of ice litter the floor. They stop every twenty feet or so to set up a survey point.

McGregor leans against a wall of ice, holding against it a measuring device that shoots a beam of red laser light to the cave’s opposite wall.

“A hundred-five” he calls out. It’s hard for the men to hear each other over the roar of rushing water. The headwaters of the Muddy Fork River tumble past.

A page from Cartaya's notebook

McGregor repeats each measurement three times for accuracy. Cartaya records the numbers in his yellow notebook and makes a quick sketch of the cave. In places, Snow Dragon is 10 feet wider than it was a year ago.

The team finishes the easy part of the survey and prepares for a tricky climb.

McGregor and Cartaya have spotted a new pair of passages shaped like keyholes in the ice about 40 feet off the floor. They’re just large enough for a person to squeeze into. McGregor belays Cartaya up the curving wall of ice so he can see where they go.

“Call it. If you think it gets stupid, we’ll just stop,” Cartaya says.

Cartaya places ice screws as he climbs and clips his rope into them for safety. But the air temperature in Snow Dragon is above 40 degrees and the screws start to melt out almost as soon as Cartaya places them.

The ice is brittle, so to avoid striking it with his axe he builds a ladder out of webbing as he climbs. An hour passes as Cartaya moves up the wall. The team watches, silent and anxious. Cartaya reaches a bulge of ice just below the passageway and sinks his axe in to pull himself up and over.

“Big fracture when I did that ….” Cartaya calls out to his friends watching from below.

If the fracture deepens, the bulge of ice could snap off with Cartaya on it. He carefully repositions his ax and pulls himself up and over. His yellow cave suit and then his boots disappear into the tube. He follows it until it dead-ends and adds another 40 feet to his map.


A Dying Glacier


A Dying Glacier

The next day, members of the expedition watch as two small figures pick their way toward the glacier across the steep heather and the piles of scree.

Andrew Fountain

Andrew Fountain has unruly hair and warm eyes and he’s wearing a bright Hawaiian shirt.

Cartaya kicks at the ice to form steps in the glacier and leads Fountain up for a look at the moulin. The scientist looks a little surprised.

“I’ve never seen anything quite like it,” he says.

He questions Cartaya about the survey work and how accurately it measures the height and width of each section of the cave. In Snow Dragon, he pulls out his camera and snaps a couple of pictures.

“Wow. Wow, wow, wow,” Fountain says, drinking in the huge empty space underneath the glacier. He tells McGregor and Cartaya he’s impressed with the changes they’ve observed.

“Your rates of enlargement over a short period of time are pretty big. It’s a small glacier, so this is a significant mass loss to these glaciers that are otherwise accounted for,” he says.

Glaciologists like Fountain study mass balance – that is, how much ice glaciers gain or lose every year. Glacier mass balance tends to be a very sensitive indicator of long-term climate trends. Before learning of Cartaya and McGregor’s work, Fountain didn’t know of any effort to track how much the ice inside a glacier melts from year to year.

“We can make measurements from the surface by satellite, Lidar, surface measurements,” he says. “But nobody’s looked at what’s happening underneath the glacier.” Their surveys, he says, could provide insight into how these glaciers are decaying.

Cartaya and McGregor pepper Fountain with questions in turn. He tells them his gut sense is that the caves are a sign of a dying glacier. Fountain says the Sandy Glacier has retreated by at least 40 percent over the last 100 years. He hazards a guess that the ice used to be about 200 feet thicker.

“It’s the thinner ice caused by climate change that allows these caves to grow really big,” he says.

He predicts that within the next decade, the caves could open up into a deep slot canyon that divides the glacier in half. The best indication of what will happen to the Sandy, Fountain says, is the story of the Paradise Ice Caves.

It’s story McGregor and Cartaya know well.


Ice Caves in Paradise

For a while, something very close to the Sandy Glacier Caves existed on Mount Rainier, just two miles from the Paradise Lodge. The Paradise Ice Caves were the most popular attraction in Mount Rainier National Park for several decades.

Paradise Ice Cave Tour

In the 1950s, mountaineering legend Lou Whittaker took thousands of people to see the ice caves. He was fresh out of college at the time. A guided summit climb cost $28. The ice caves were just $5. Few people climbed Rainier back then.

“We’d rappel off the balcony on the lodge and land on the floor and say, let us tell you about the ice cave trips, and see if we could talk them into the five dollar fee,” Whittaker says.

Whittaker still vividly remembers the caves. “You could walk in 200 feet and still get this eerie green blue light which was awesome to see. And the cold air, even on a real hot day,” he says.

Two factors determine whether a glacier advances or retreats: how much snow falls in the winter and how warm it is during the summer.

Most glaciers in the Northwest have been retreating since a little ice age in the 1800s came to an end, They’ve retreated more quickly as carbon has accumulated in the atmosphere and average temperatures here have risen.

The Paradise Glacier thinned so dramatically that a band of rock split the glacier in two, leaving the lower half starved of ice. The caves formed beneath the thinning ice. In 1940, the park’s naturalist wrote that the lower Paradise Glacier was stagnant and predicted it wouldn’t last long.

But the 1950s and 1960s were good decades for snow at Rainier, and many of the glaciers there stopped retreating.

By the late 1970s, big holes opened in the ceiling of the caves, and they grew more dangerous. Within two decades, the lower half of the Paradise Glacier had melted.

The ice caves were gone.

“We live in a warming period. And times, they are a changing,” Whittaker says.

Paul Kennard, one of the park’s geologists, visited the Paradise Ice Caves in 1981, when very little of the glacier was left. At the time, he wasn’t alarmed.

“I think we saw the variations in the glaciers as just being a normal thing” he says. “We didn’t see this long term trend.”

Now, Kennard says, he sees it as a reflection of global climate change. Every one of Rainier’s glaciers is at its historic minimum. Between 2003 and 2009, Rainer lost ice six times faster than it had in previous decades.



Back at Mount Hood’s Sandy Glacier, Fountain takes up his trekking poles for the hike down. He leaves Cartaya and McGregor with advice for improving their study: Set up stakes and start measuring the surface snowmelt so they can see how that compares to the rate at which the caves grow.

Those rates have McGregor and Cartaya wondering how much longer the caves will be around. Of all the places they have surveyed, the moulin has changed the most dramatically.

Surveying the moulin was difficult to pull off, due to the rock fall danger and the freezing water that flows down the side of the pit during the day.

Cartaya and McGregor waited until midnight, hoping the lower temperatures would minimize the risks.

Lit up by headlamps, the team headed up the steep slope, a little train of light moving up the dark flank of the mountain. McGregor dangled in the middle of the moulin like a spider on a line of silk, using his laser beam to measure the circumference in cross sections as he descended. Water streamed down the sides of the pit and drenched him as he worked.

A few weeks later, when Cartaya gets a chance to calculate the size of the moulin, he gets a sobering result: It’s about about four times larger than it was last year.

“In one way it’s exciting, because it means when we come back we’ll be able to document bigger and more frequent changes,“ Cartaya says.

On the other hand, he adds, “it’s kind of like losing a friend.”