Interstate 80 is under a rolling closure from Rock Springs to just west of Cheyenne. The closure was issued at 9 a.m. and was expected to last 15 to 17 hours.
That's according to the National Weather Service in Riverton which is predicting a temperature drop that could see freezing weather in Casper this weekend.
The Wyoming Department of Health recommends that the elderly, young children and people with respiratory problems avoid excessive physical exertion and minimize outdoor activities.
The weather service is expecting winds of between 15 and 25 miles per hour in the affected areas with gusts up to 35 mph. Humidity may get as low as 14%.