US-81 (OK)

U.S. Route 81
Chisholm Trail Historic Route
US-81 highlighted in red on a road map of Oklahoma
Route information
Maintained by ODOT
Length:	229.28 mi (368.99 km)
Existed:	December 7, 1926 – present
Major junctions
South end:	US 81 south of Terral
	I‑44 / H.E. Bailey Turnpike in Chickasha I‑40 in El Reno
North end:	US-81 south of Caldwell, Kan.
Highway system
United States Numbered Highway System List Special Divided Replaced Oklahoma State Highway System Interstate U.S. State Turnpikes ← SH-80 SH-82 →

U.S. Route 81 (abbreviated US-81) is a north–south U.S. highway running through the central United States' Great Plains region, from Fort Worth, Texas to the U.S.–Canadian border at Pembina, North Dakota. A 229.28 miles (368.99 km) segment of the highway lies within the state of Oklahoma. US-81 crosses the Red River from Texas south of Terral, passing through several Oklahoma cities, such as Chickasha, El Reno, Kingfisher, and Enid, before entering Kansas north of Renfrow.

The route of US-81 was originally served by the Chisholm Trail, which was used to drive cattle from Texas to Abilene, Kansas. US-81 was established as a primary route of the U.S. highway system at the time of the system's original designation. US-81 was established through Oklahoma on December 7, 1926.

US-81 enters the state of Oklahoma from Montague County, Texas by crossing a bridge across the Red River into Jefferson County. Just north of the river, the highway passes through Terral, its first Oklahoma town. The route takes a due north course north of Terral, with a Union Pacific rail line, which US-81 will parallel throughout its time in Oklahoma, lying just to the west of the highway, and the Red River running to the west of that. US-81 has its first highway junction in Oklahoma in Ryan, where it serves as the western terminus of State Highway 32 (SH-32). North of Ryan, the highway begins paralleling Beaver Creek, a tributary of the Red River, and bypasses Sugden to the east. US-81 intersects US-70 on the southeastern outskirts of Waurika, the county seat of Jefferson County. As US-81 passes north of the town, it begins roughly following the course of Cow Creek, which spills into Beaver Creek in Waurika. The highway curves northeast to bisect Addington before returning to a due north course as it enters Stephens County.