Vail Pass is closed eastbound at mile marker 180 for avalanche mitigation.
Operations are expected to take hours with an unkown time of reopening.
The Colorado Department of Transportation has planned helicopter operations throughout the day, including Vail Pass.
“The Colorado Avalanche Information Center has identified many mountain ranges in western Colorado as being at high risk for avalanche slides,” CDOT said in a news release. “It is very likely that a natural slide could occur and motorists should plan for unexpected closures as well. There is also the possibility of large debris fields with trees and rocks mixed with snow in these slides, which can take maintenance operations longer to clear.”