Heavy snowfall, along with blowing and drifting snow, closed portions of Interstate 80 between Cheyenne and Laramie, as well as much of Interstate 25 between Cheyenne and Casper, AccuWeather.com reported.
Many other roads and highways throughout the state that weren't closed outright were listed as "No Unnecessary Travel," officials said.
Snow shifted north of the Denver area Tuesday, but forecasters said another wave of snow would begin falling during the day on Wednesday and into the night.
To the east, the South Dakota Department of Transportation reported most of the state's highways were slippery from ice, snow and water early Wednesday.
Snow was falling steadily across much of South Dakota, from Rapid City through Pierre and up to Aberdeen, early Wednesday, weather officials said.
Officially, a record 5.4 inches of snow fell in Cheyenne Tuesday, topping the 4.5 inches that fell in 1940, AccuWeather.com reported. As of Tuesday, the city has had 22.3 inches of snow so far in April; the average is 6.3 inches.