From the AccuWeather.com site:
Blizzard Shuts Down I-25 and I-90 in Wyoming, South Dakota
AccuWeather.com reports blizzard conditions will continue to affect eastern Wyoming, western South Dakota and northwestern Nebraska Friday, shutting down travel. In some areas, the snow will fall at the rate of 1 to 2 inches per hour.

A storm responsible for bringing record rainfall to parts of the Northwest last weekend will blast areas from the Rockies to the Plains and Midwest with snow, wind, rain, severe thunderstorms and tornadoes through Saturday.

Portions of I-25 and I-90, as well as U.S. routes 16 and 20 in central and eastern Wyoming, have been closed Friday due to hazardous conditions, according to the Wyoming Department of Transportation.

No travel is advised along I-90 in South Dakota between exits 46 and 55 until the midday hours Saturday, according to the South Dakota Department of Transportation.

Difficult travel is occurring along much of I-80 and I-25 in Wyoming and I-90 in western South Dakota with snow- and slush-covered roads and poor visibility.

Rapidly accumulating snow, blowing and drifting snow and whiteouts may cause some ill-prepared motorists to get stuck or become disoriented. The storm will remain intense enough to close additional roadways for a time in Wyoming, as well as in South Dakota and Nebraska.

Wind gusts of 40 to 60 mph, both with and without heavy snow, can also down trees and power lines.