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Ice cave

The Ice Cave in the Big Snowy Mountains is 100 feet wide and 75 feet long. The roundtrip hike up to the cave is 12.3 miles.

There is more to the Big Snowy Mountains than meets the eye. The true distinctive qualities that make it a gem for the area lie beneath the surface, painted in smooth strokes of ice.

The Big Snowies are an island range just south of Lewistown. The highest point, Great House Peak, rises to 8,681 feet.

True to their island range name, they jut out of the flat prairie with spectacular green ridges and clear water.

The area is a geographic marvel. The Big Snowies are one of only a handful of "psuedo-cirques" in the world. A cirque is a steep hollow point at the end of a valley or carved into a mountainside. A cirque is typically formed by glacial erosion. However, the psuedo-cirques of the Big Snowies were believed to be formed by landslides of heavy limestone resting on smooth shale rock layers.

The mountains are part of a 98,000-acre wilderness study area — one of 44 in Montana and one of seven managed by the Forest Service.

Ice caves

The Ice Caves of the Big Snowies are the pinnacle of an arduous hike. The Ice Caves Loop is an approximately 12.3-mile hike with a 2,143-foot elevation gain in the first three miles.

Dave Byerly, a Lewistown resident and the Montana Wilderness Association's go-to expert on the range, says not to be discouraged by the climb.

"Hiking is always easier when there are big views," Byerly said.

The Big Snowies aren't wanting for big views.

The hike

A recent hike led by Montana Wilderness Association member Sadie Russell was part of the group's "Discover Wild Montana" wilderness walks program. 

Robin Morris, a hiker who traveled more than three hours to attend the hike, said the Ice Caves have been on her bucket list for years.

Even Gerry and Chuck Jennings, active members of the MWA and avid outdoorsmen, remarked that they haven't made it back to the caves since their first and only trip more than 30 years ago.

The group set off on the steep terrain. The first two miles led the group through lush forest ripe with beds of white lady slippers, bluebells and vibrant orange mountain lilies.

The trail, in large part, was built by the Civilian Conservation Corps in the early 1930s during the Great Depression.


The Big Snowies are home to some big game.

"There's a great population of elk and one of the largest populations of black bear," said Ron Wiseman, Judith Mussellshell District ranger. "One of the largest — if not the largest — black bears ever harvested was found here."

But what Wiseman is most excited about is the rumored return of mountain goats.

Montana Fish, Wildlife and Parks made an effort to reintroduce mountain goats to the area years ago, but the mountain lions ate most of them. Wiseman said his office receives a call every few years about someone spotting a single goat in the mountains.

"It's been years since we've heard of even one mountain goat," Wiseman said. "This year people were taking pictures around Greathouse Peak and saw eight."

Wiseman encourages anyone who sees or photographs a mountain goat (or eight) to call the ranger station with the details.

Ridge top

In a single file line the group rounded a seemingly infinite switch back and suddenly the mountain opened up. They rounded their final climbing curve, signifying their presence atop the ridge and collapsed into the slate rock piles to scarf down a quick lunch and look out over the whole state of Montana.

To the north, the Judith and the Moccasin mountain ranges rose from either side of Lewistown.

"One hundred years ago, up until just a few decades ago, there was gold in them there hills — as they say," Byerly said. "At one time there were thousands of miners up there. In the old photos, the Judiths didn't have trees. The Snowies, for whatever reason, never had gold. It's not logging country either because they're too steep. The area was consequently protected."

After some jerky and a few big gulps of water, the crew carried on. The Ice Caves were still another 2 miles across the ridge.

Walking the top

The landscape completely changed.

The forest gave way to loose shale that eventually turned into a mountain-top prairie with sparse trees. 

On a clear day hikers atop the ridge can see from Canada to Wyoming. It's possible to see the Bull Mountains (near Roundup), Absarokas (near Billings), Crazies (near Bozeman), Beartooths (near Red Lodge), Castles (near White Sulphur Springs), Big Belts (near Helena), Little Belts (near Neihart), Sweet Grass Hills (near Sunburst), Highwoods (near Great Falls), Bear Paws (near Rocky Boy's Reservation), North Moccasins (near Lewistown), South Moccasins (near Lewistown), Judiths (near Lewistown) and the Little Rockies (near Lodgepole).

On this day the hikers could barely see into Wyoming.

The group walked the spine of the ridge for two more miles before reaching a junction in the trail that would lead them down to the cave.


Then, finally, they stood at the cave's mouth and felt the cool air percolating out of the opening in the rock face. A long tongue of snow stretched down into the darkness.

The group made their way in, skirting along the exposed dirt to either side of the ice and clinging to the walls for support. A tall pillar of ice stretched from floor to ceiling on the left side of the 100-foot wide cave. A pristine swath of white ice coated the entire cave floor.

The temperature inside the cave is about 40 degrees cooler than the air outside. That's part of what keeps the ice frozen all year.

According to research conducted by Jim Foster and Rod Benson for Earth Science Picture of the Day, a nonprofit research corporation for cross-disciplinary study of science and technology, air density is the primary factor in maintaining ice in the cave.

Cold air is heavier than warm air, so when it flows into the cave it sinks to the bottom. Because the air must descend into the cave, it is too heavy to rise back out and instead keeps the area cool as water seeps through the porous limestone and freezes into ice.

While some explored the cave, others looked around for fossils along the trail. Rocks with embedded prints of different shells and barnacles were collected and showed off among the hikers.

The ice of the Ice Caves signify the true value of the mountains. The water that misses the caves but still purifies itself in the Madison limestone eventually makes its way down and becomes the headwaters of Big Spring, a water source for Lewistown and the surrounding area.

The spring pumps up to 64,000 gallons a minute or about 90 million gallons of water a day.


Though the Ice Caves seem like the pinnacle of the hike, they are only one of the highlights of the trail. From the junction where hikers can turn off to travel down to the cave, there are still seven miles to go to complete the hike.

The trail takes hikers along the ridge to the breathtaking vista of West Peak before winding down through the forest, making a quick stop at Grandview Point before returning to the trailhead at the top of Crystal Lake.