Colorado Avalanche Buries Highway

Eight People Rescued From Two Cars Swept Off Thoroughfare Near Berthoud Pass

DENVER, Jan. 6 -- An avalanche roared across a mountain highway on the Continental Divide on Saturday morning, sweeping two cars off the road near Berthoud Pass, Colo., onto a steep downward slope but causing only one serious injury.

People from nearby cars dug frantically into the instant mound of snow and debris on the road to free the eight passengers in the two cars that were hit, police said.

The cascade of snow, rocks and trees that came rushing down the side of Stanley Mountain about 10:30 a.m. covered all three lanes of U.S. 40. That was just after the normal Saturday "rush hour" on the road, a key thoroughfare linking Denver and Interstate 70 with the ski resorts of Winter Park and Steamboat Springs.

"We have recovered two vehicles that were driven over the edge of the highway," said Colorado State Patrol spokesman Eric Wynn. The state patrol said eight people were taken to hospitals, but the worst injury incurred was apparently a broken leg.

The pass was reopened to traffic Saturday night.

The Colorado Department of Transportation said the slide divided into two streams as it advanced down the mountainside, and thus both cars were hit at almost the same moment.

A large snowslide can reach speeds of 80 mph. A driver who saw or heard the avalanche coming might not have been able to avoid it.

Unlike Denver, about 50 miles to the east, the Berthoud Pass area has not had unusually heavy snowfall so far this winter. Still, weather conditions have been conducive to an avalanche, according to the Colorado Avalanche Information Center.

The dangerous combination that produces big winter slides is a series of warm sunny days followed by cold nights, the center says. In those conditions, the snow surface tends to melt during the day and then freeze into a slab of ice at night. When new snow falls onto that icy slab -- about 12 inches fell on the Berthoud Pass area in the past two days -- the soft snow can easily slide downhill, picking up more snow as it builds momentum.

A major avalanche will tear away large boulders and whole trees as it races downhill, adding to the enormous weight of the slide.

If conditions are right, a slide can be triggered by wind, by passing animals or by the wake of a skier or snowboarder. Although there is no longer a ski resort on Berthoud Pass, the area -- part of Arapaho National Forest -- is extremely popular with backcountry enthusiasts, particularly on a clear winter Saturday morning.

The U.S. Forest Service does not block access, but there are signs noting that the slopes reaching upward toward Berthoud Pass are well-known avalanche chutes. Fourteen months ago, a backcountry snowboarder and his dog were killed there when his board started a snowslide that caught up with him and buried him halfway down the hill.

To accommodate the ski areas, as well as extensive second-home developments in the Fraser Valley north of Winter Park, Colorado has spent large sums in the past decade to improve and widen U.S. 40 as it winds up and over 11,315-foot Berthoud Pass. The road over the pass now has three wide lanes, with the center lane reserved for uphill traffic to allow cars to pass slow-moving trucks or snowplows. A driver on U.S. 40 sees a forested mountain rising steeply upward on one side of the car, and a steep drop-off on the downhill side of the road. Large retaining walls of stone and brick have been erected to protect cars from rockslides and snowslides.

Accordingly, avalanches that cover U.S. 40 are unusual.

At the Loveland ski area, 25 miles west of Berthoud Pass, resort owners tried in vain for years to get permission from the U.S. Forest Service to build a new ski run. Then an avalanche swept through, dumping tons of snow and trees into Loveland's parking lot and leaving the slope completely cleared.

The resort then opened an expert slope on the treeless patch of hill. It calls the run "Avalanche Bowl."