Some of  Colorado's busiest highways are closed as a  storm brings blizzard conditions.

Many schools and state offices were shut down yesterday and the blizzard is expected to impact Colorado, Wyoming, Montana, Nebraska, and South Dakota.

In Colorado, 22 miles of Interstate 25 near the Wyoming border was closed, and 66 miles of Interstate 70 was closed to westbound traffic.

Vehicles are required to have chains to cross several mountain passes in Colorado and so far three entrances to Rocky Mountain National Park were also closed.

About 1350 flights into Denver have been canceled as a winter storm hits the western U.S., with blizzard conditions expected to engulf parts of Colorado, Wyoming, Montana, Nebraska, and South Dakota.

State and local government workers in Denver were told to stay home and many colleges also closed. The National Guard has been asked to help more than 1,000 stranded drivers on Colorado highways.