US 20 highlighted in red, with its unofficial segment through Yellowstone National Park highlighted in blue | ||||
Route information | ||||
Maintained by WYDOT | ||||
Length | 434.003 mi[1] (698.460 km) | |||
Restrictions | Intermittent closures during winter | |||
Major junctions | ||||
West end | Eastern entrance of Yellowstone National Park | |||
East end | ![]() | |||
Location | ||||
Country | United States | |||
State | Wyoming | |||
Counties | Park, Big Horn, Washakie, Hot Springs, Fremont, Natrona, Converse, Niobrara | |||
Highway system | ||||
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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.