Days of heavy snow and strong winds have created a high and growing avalanche risk across Colorado’s mountains, with three accidents and two deaths in the past 10 days. The greatest risk is in the mountains west from Frisco to Grand Junction and south from Steamboat Springs to Durango, according to the Colorado Avalanche Information Center.
“We are in the middle of a big avalanche cycle,” said Ethan Greene, director of the Boulder-based avalanche center. “We are in a pretty dangerous situation.”
On Dec. 14, Cory Brettmann, 52, a former Aspen ski patroller, died in an avalanche while backcountry skiing on Richmond Ridge, just south of Aspen Mountain.
The same day, Matt Jones, while skiing on a trail in Vail’s Blue Sky Basin, was caught in a 3-foot-deep slide that buried him to his waist. A friend dug him out uninjured.
Vail Resorts closed the basin, which it had just opened, to investigate and perform additional avalanche control. The area was then reopened, according to company spokeswoman Liz Beibel.
Last week, Michael Bowen, 36, of Crested Butte was killed in an avalanche while snowboarding just outside town on Mount Emmons in an area called Happy Chutes.
“It is snowing heavily, the winds are blowing and it’s cold,” Shelly Grail, snow ranger for the U.S. Forest Service’s Dillon District, said Tuesday. “That’s a perfect formula for avalanches.”
The seeds of the current threat were sown in early October snows that were followed by a warming that created a “weak zone” of “sugary snow.” Then came rain that froze.
“So we have these unstable and hard layers that when they flex will break apart,” said the avalanche center’s Greene.
Then came days of heavy snow with as much as 12 feet at Vail this season and 17 inches overnight Monday.
“The avalanche danger in the state of Colorado doesn’t change very quickly,” said Alan Bernholtz, director of the Crested Butte Avalanche Center.
Crested Butte has received 100 inches this season and 18 inches in 24 hours.
“We’ve had high danger levels for a week,” Bernholtz said. “It stops snowing, and the snowpack settles a little, and then it starts snowing again.”
The last element needed for an avalanche is a “trigger,” which can be a skier or snowmobile moving across the zone.
On Tuesday, the southern San Juan Mountains were upgraded to high risk by the avalanche center after receiving 2 feet of snow in the previous 24 hours.
Grand Mesa, which got 15 inches of snow, and Aspen, with 21 inches, also were upgraded to high risk by the center.
“This is really a time to be careful. The risk is widespread,” said Dillon snow ranger Grail.
Since 1950, Colorado has led the nation in avalanche-related deaths with 221. That is more than the next two states — Alaska and Washington — combined, according to avalanche center data.
The state’s cold, dry climate, high elevation, winds and sporadic snows — known as a continental avalanche climate — combine with the large number of people in the backcountry to create the greater risk, Greene said. In contrast, the maritime climate of the Pacific Northwest’s Cascade Range tends to lead to bigger dumps of snow and higher temperatures.
“There is an avalanche risk during and right after the snowfall, but it then dissipates quickly,” Greene said.
If it keeps snowing heavily in Colorado, the weight of the snow could stabilize the weak base, said Spencer Logan, an avalanche center forecaster.
“That would take time,” Logan said. “Reducing avalanche risk takes time. But for now, as long as it is snowing, it is risky.”
Mark Jaffe: 303-954-1912 or mjaffe@denverpost.com
Backcountry safety
• Skiers and snowboarders venturing into the backcountry should have first completed an avalanche education class. Information on classroom training and an online course can be found at .
• Equipment for a backcountry trip should include an avalanche transceiver, probe pole, rescue shovel, first-aid kit and a cellphone.
• Do not go alone.
• Before you head out, check the avalanche forecast in addition to the weather forecast. Both can be found online at .
