INDEPENDENCE PASS – Plumes of snow and the booms of exploding “turkey bombs” rose from the east side of pass Thursday morning as the Colorado Department of Transportation worked to clear snow from avalanche chutes above the road.
Four-person helicopter crews dropped the bombs, which resemble frozen turkeys and weigh about 40 pounds each, on a cornice that posed an avalanche risk to CDOT plow crews along a ¾-mile stretch of Colo. 82 known as the Beeler Grade.
Arming the turkey bombs with a 2-minute, 45-second fuse, the crew dropped the charges on the cornice, gained at least 1,000 feet of altitude and waited to see the plume, hear the boom and judge whether the bomb successfully dislodged snow.
The charges usually stay put in the snow, but sometimes they roll. Four years ago one tumbled down an avalanche chute, continued across the road and detonated in a snowfield a quarter mile from observers on the ground.
CDOT planned to drop about 40 of these bombs Thursday to stay on schedule to clear the pass by May 25, which is the Thursday before Memorial Day and the traditional date to reopen the 12,095-foot road over the Continental Divide.
Crews operating plows and snowcats began to clear the pass from the Twin Lakes side Tuesday, a week earlier than normal because of snowy weather forecast for the coming week, said Jack Stieber of CDOT’s avalanche specialty unit.
Although the cornice stood 20 feet tall, the avalanche risk along the Beeler Grade has been worse in previous years, said Colorado Avalanche Information Director Ethan Greene.
Wet snows that Central Colorado received in January and February had consolidated into a layer that recent storms have topped with 20 inches of dry snow, Greene said.
While the cornice above the Beeler Grade has sent house-size chunks of snow careening toward the road and let loose more minor slides as late as June, the overhanging ledge of snow would be more likely to partially bury equipment and less likely to cause serious injury this year, Greene said.
After two hours of periodic explosions along the Beeler Grade, the helicopter lifted off from the highway and followed Mountain Boy Gulch toward the Aspen side of the pass, where another crew of CDOT workers waited for the aircraft to drop more bombs on more snow.