A heavy overnight snowstorm has closed many Colorado highways and several mountain highways after over eight inches of snow fell in some areas and more snow continued to fall Wednesday morning.

Travelers should not attempt to use county or secondary roadways to bypass highway closures, the Colorado Department of Transportation advised.

The following highways are closed due to adverse conditions:

Interstate 70 in both directions from Airpark Road to Kansas.

U.S. 36 in both directions from Last Chance to Kansas.

Interstate 76 in both directions from Sterling to Nebraska.

U.S. 385 in both directions from Julesburg to Nebraska.

U.S. 40/U.S. 287 in both directions from Limon to Kansas.

U.S. 138 in both directions from Sterling to Nebraska.

U.S. 24 in both directions from Colorado Springs to Interstate 70.

U.S. 6 in both directions from Sterling to Nebraska.

Colo. 113 in both directions from Colo. 138 to Nebraska.

Colo. 59 in both directions from Interstate 76 to Yuma.

Colo. 55 in both directions from Colo. 138 to mile post 5.5.

Colo. 52 in both directions from Colo. 14 to Fort Morgan.

Colo. 71 in both directions from Last Chance to Brush.

Colo. 23 in both directions from U.S. 385 to Nebraska.

Colo. 14 in both directions from Ault to Sterling.

Colo. 11 in both directions from Colo. 138 to Nebraska.

Colo. 86 in both directions from Elizabeth to Interstate 70.

Mountain and southwestern Colorado Closures:

U.S. 550 Purgatory to Ouray (Red Mountain, Molas and Coal Bank passes).

U.S. 160 Wolf Creek Pass.

Colo. 65 Grand Mesa.

Colo. 139 at Douglas Pass is closed due to avalanches.