U.S. Route 287 (US 287) is a part of the U.S. Highway System that travels from Port Arthur, Texas northwest to Choteau, Montana; broken into two segments by Yellowstone National Park where unnumbered park roads serve as a connector. In the state of Wyoming, it extends approximately from the Colorado state line near Tie Siding to the southern entrance of Yellowstone National Park.
US 287 enters Wyoming about south of Tie Siding; about a mile north of the state line it crosses Pumpkin Vine Hill (elevation ), a pass between the Laramie Mountains to the east and the Medicine Bow Mountains to the west. US 287 reaches Laramie where it crosses I-80 and begins a concurrency with US 30. The two highways head north for to Medicine Bow, then turn west-southwest for and return to I-80 near Walcott, where they merge with the interstate west for to Rawlins. US 287 branches off from I-80 and US 30 and heads into Rawlins concurrent with I-80 Business and US 30 Business. In downtown Rawlins, US 287 departs the Business Route and merges with WYO 789 to form a concurrency to Lander. US 287 heads northwest from Lander for to Diversion Dam Junction, about west of Morton, and merges with US 26 were they continue west to Dubois.
West of Dubois, the routes become part of the Wyoming Centennial Scenic Byway, and they enter the very mountainous terrain of West Central Wyoming, crossing the Continental Divide at Togwotee Pass and enter Grand Teton National Park. At Moran, US 287 concludes its a concurrency with US 26 and becomes concurrent US 191 and US 89. The three routes travel north unsigned along side Jackson Lake. Leaving Grand Teton National Park, they travel through John D. Rockefeller Jr. Memorial Parkway before reaching the South Entrance of Yellowstone National Park. Officially US 287 and other U.S. Routes are officially discontinuous through the park, though some commercially produced maps show these highways running inside Yellowstone National Park itself along its unnumbered roads. US 287 along with US 191 resume at the West Entrance at West Yellowstone, Montana.
The section of US 287 between Laramie and the Colorado state line was originally commissioned as US 285 in 1926, with it to continue to Denver. It was renumbered to US 287 in 1936.
U.S. Highway 287 Bypass (US 287 Byp.) serves as a bypass for Rawlins.