US 16 in Wyoming crosses through the towns of Newcastle and Upton before joining I-90 near Moorcroft. It runs concurrently with I-90 to Gillette, where it splits off north and then arcs back down to the town of Buffalo. From Buffalo it goes over the Powder River Pass on its way to Worland. In Worland, it turns north and overlaps US 20 through the towns of Basin and Greybull. In Greybull, the two routes combine with US 14 and go west to Cody and into Yellowstone National Park. For most of the way it is a two-lane road.