Avalanche cannons along Colorado's I-70 retired, replaced with new remote control system

The booms echoing through Colorado's high country each winter are getting a high-tech upgrade. For years, crews with the Colorado Department of Transportation used howitzer cannons along I-70 to blast avalanche paths near the Eisenhower and Johnson Tunnels, in order to trigger small slides before they could threaten drivers below.

Now those cannon blasts are a thing of the past, at least up in the northern mountains.

In place of artillery, CDOT has installed three new remote avalanche control systems on Bethel Mountain, built by Wyssen Avalanche Control. The $800,000 project uses towers loaded with precision-placed explosives, 12 charges each, all of which can be detonated remotely with the push of a button.

"One push...will clear seven miles of interstate," Brian Gorsage, Avalanche Program Manager for CDOT, said.

A helicopter delivers the preloaded charges to the towers before the winter season, and once snow builds up, CDOT can trigger the devices from a safe distance, even before sunrise, when there's less traffic on the interstate.

"Because of the size of the bang you just witnessed, we were able to remove eight artillery targets with two towers," Gorsage said. "The third tower was just a bonus. The only way we could mitigate that one before was with helicopter bombing, due to some cabins on the other side of the ridge."

"At four in the morning, we'll take care of several paths with remote units and have as little impact to traffic as possible," Gorsage said. "If we're doing it right, the public won't even know we were here."

CDOT shared that there are now 49 remote avalanche control systems in operation across the state, with the hope of installing more over time. Crews track nearly 500 slide paths along interstates and highways statewide. 

"This represents another step toward improving safety and resiliency on one of Colorado's most important routes," CDOT said in a press release.