U.S. Route 177 is a spur of U.S. Route 77. It currently runs for 233 miles (375 km) from South Haven, Kansas at U.S. 81 to Madill, Oklahoma at U.S. 377. It passes through the states of Kansas and Oklahoma.

Originally, the highway functioned as a shortcut for Wichita to Oklahoma City traffic traveling between U.S. 81 at South Haven, KS and U.S. 77 at Three Sands Jct, Oklahoma (where U.S. 77 and Oklahoma State Highway 156 intersect outside Marland, Oklahoma today).

During the 1960's, the highway was extended south to Madill, Oklahoma, replacing the entire length of Oklahoma State Highway 40 from Ponca City, Oklahoma to then-U.S. Route 66 (near Wellston, Oklahoma) and the portion of Oklahoma State Highway 18 between Shawnee, Oklahoma and Madill, Oklahoma (the segment between U.S. 66 and Shawnee was constructed at this time). Vestiages of the these highways remain in spur routes Oklahoma State Highway 40A, located entirely in Carney, Oklahoma and Oklahoma State Highway 18A, located south of Sulphur, Oklahoma.

During this extension, the alignments of U.S. 77 and U.S. 177 was altered in North Central Oklahoma as follows:

U.S. 77 was relocated to run north from Three Sands Jct to Tonkawa, Oklahoma on the former route of U.S. 177, then east on U.S. 60 to Ponca City, Oklahoma. This also involved a new U.S. 60 alignment between Tonkawa, Oklahoma and Ponca City, Oklahoma, where U.S. 60, U.S. 77, and U.S. 177 are all triplexed on the same highway (which results in northbound U.S. 77, eastbound U.S. 60, and southbound U.S. Highway 177 traffic running in the same compass direction - east)

Principal cities and highway intersections

• Ponca City, Oklahoma - U.S. 60
• Stillwater, Oklahoma
• Shawnee, Oklahoma - Interstate 40, U.S. 62, U.S. 270

References