U.S. Highway 20 (US 20) is an east–west highway in the state of Wyoming. The eastern segment of US 20 in the state starts at the eastern entrance to Yellowstone National Park along with the western terminuses of US 14 and US 16. US 14/US 16/US 20 runs east to Greybull, where US 14 continues east and US 16/US 20 turns south; at Worland, US 16 turns east while US 20 continues south, passing through Wind River Canyon south of Thermopolis. US 20 joins US 26 in Shoshoni, where it turns east and continues all the way through Casper. From Casper, US 20/US 26 parallels Interstate 25 (I-25) and US 87 for 26 miles (42 km), until all four link up together just southeast of Glenrock. I-25/US 20/US 26/US 87 stays combined to Orin, where US 20 turns east from I-25, at the western end of US 18. US 18/US 20 run concurrently from Orin to Lusk, where US 18 turns north and US 20 continues east into Nebraska.

Interstate 25 (I-25) is a part of the Interstate Highway System that runs from Las Cruces, New Mexico, to Buffalo, Wyoming. In Wyoming, the Interstate Highway runs 300.530 miles (483.656 km) from the Colorado state line near Cheyenne north to its national terminus at I-90 near Buffalo. I-25 connects Wyoming's largest city and capital, Cheyenne, with its second largest city, Casper, and the smaller communities of Wheatland, Douglas, and Buffalo. The highway also connects those cities with Denver and Billings via I-90. I-25 runs concurrently with U.S. Route 87 (US 87) for almost its entire course in Wyoming. The highway also has extensive concurrencies with US 20 and US 26 along its east–west segment through the North Platte River valley. The Interstate has business loops through Cheyenne, Chugwater, Wheatland, Douglas, Glenrock, Casper, and Buffalo.