KUSA – Westbound Interstate 70 closed at Copper Mountain Monday afternoon due to a semi-fire on Vail Pass, according to the Colorado Department of Transportation.

The closure, which began at around 1:15 p.m., is expected to last between two to four hours, Colorado State Patrol tweeted.

Traffic cameras in the area showed long backups, as well as fire department activity.

CSP recommends taking Highway 91 to Highway 24 as an alternate route.

There’s no word yet if anyone was injured in the semi fire, or what caused it in the first place.