Snow fills Colorado mountains. Crews are throwing explosives at it.

ASPEN, Colo. – The turkey-sized bomb dropped out of the hovering helicopter and plopped onto the soft snow below.

Handmade by state workers, the duct-taped wrapped bomb sat silently for just over two minutes as the helicopter retreated to a safe distance and the fuse burned away atop Independence Pass.

Then with an explosion seen but not yet heard, the bomb blasted snow and rock more than 100 feet into the air, triggering a snow slide.

Seconds later, the explosion echoed off the rocky cliff walls and surrounding valley as the avalanche cascaded down – water in solid form but still flowing like a river, piling across the two-lane road below.

Hover. Toss. Explode. Slide.

WATER CRISIS: Experts warned the Great Salt Lake was about to disappear – then came a wet winter. What now?

READ MORE Water levels are going up in the West's massive reservoirs. Has the water crisis been averted?

In a process repeated dozens of times, workers with Colorado's Department of Transportation blasted avalanches down gullies and onto the empty, closed road.

Why are crews creating avalanches?

By setting off avalanches while the road remained closed for the winter, workers hoped to prevent unexpected slides later that could trap drivers once the road opens around Memorial Day.

Workers watched the blasts and slides from a safe distance, wearing safety beacons so rescuers could find them if they accidentally got buried by the snow.

"It's been a ton of work to keep roads clear," said Brian Gorsage, the state's avalanche coordinator. "These roads across the West have been buried from exceptional snowfall. There's so much snow."

Crews like this one are working across the West to open high-elevation roads and mountain passes following an extraordinarily snowy year. While most East Coast residents had a warm winter, Colorado, California, Utah and other western states saw heavy snowfall that tallied in some places more than 70 feet over the course of the season.

An annual safety project

This particular area of Colorado's mountains saw about average snowfall this winter. The road across Independence Pass snakes along multiple switchbacks carved into the mountains, and deep avalanche gullies overhang along large sections.

Avalanche blasting here is an annual process needed to open the road safely.

As the snow warms and begins to melt, the compacting layers can more easily slide, sending tons of snow onto the road below. Triggering slides with explosives ensures the snow runs off before any drivers are threatened. During the winter, crews across the west struggled to keep up with the work, and many roads that are ordinarily open in the winter were closed for hours, if not days.

"A lot of these crews have put in two weeks, three weeks straight," Gorsage said.

This article originally appeared on USA TODAY: Controlled avalanches in Colorado used to keep drivers safe