Near unincorporated Pearson, SH-59 splits off to the east. US-177/SH-3W continue north to Tecumseh, where they have an interchange with SH-9. At this interchange, US-270 joins the concurrency. The three highways run along the west side of Shawnee. At the Interstate 40 interchange, SH-3W reunites with SH-3E, and the unified SH-3 (along with US-270) follows I-40. US-177 continues northward alone.
In Payne County, US-177 almost immediately passes through the town of Perkins. North of that community, it has a one-mile (1.6 km) concurrency with State Highway 33. It then passes through the county seat, Stillwater, the home of Oklahoma State University. There, it intersects SH-51. North of Stillwater, it serves as the western terminus of the Cimarron Turnpike Spur. Farther north, in Noble County, it crosses US-64 and the mainline of the Cimarron Turnpike. It then has a four mile (6.4 km) concurrency with State Highway 15.
US-177 then enters its final county in Oklahoma, Kay County. It serves Ponca City, where it begins a wrong-way concurrency with its parent, US-77, as well as US-60 (which is signed the "correct" direction). The routes split near Tonkawa. US-177 then runs through Blackwell and Braman. North of Braman, the route is the northernmost exit on Interstate 35 in Oklahoma. Six miles (9.7 km) after the I-35 junction, US-177 leaves Oklahoma.
Kansas
US-177's northern terminus in South Haven, Kansas
US-177 then enters Sumner County, Kansas near Hunnewell. Only 4 mi (6.4 km) north of the state line, US-177 ends at US-81 in downtown South Haven, Kansas. The terminus is less than a mile from the western terminus of US-166 (also on US-81) north of town.
History
Originally, the highway functioned as a shortcut for Wichita to Oklahoma City traffic traveling between US-81 at South Haven, KS and US-77 at Three Sands Jct, Oklahoma (where US-77 and State Highway 156 intersect outside Marland, Oklahoma today).
During this extension, the alignments of US-77 and US-177 were altered in North Central Oklahoma as follows:
US-77 was relocated to run north from Three Sands Jct to Tonkawa, Oklahoma on the former route of US-177, then east on US-60 to Ponca City, Oklahoma. This also involved a new US-60 alignment between Tonkawa, Oklahoma and Ponca City, Oklahoma, where US-60, US-77, and US-177 all overlap on the same highway (which results in northbound US-77, eastbound US-60, and southbound US-177 traffic running in the same compass direction: east).
State Highway 40A is an 0.35-mile (0.56 km)[4] highway in Lincoln County, Oklahoma. It is numbered after State Highway 40, the predecessor to US-177. It is the shortest state highway in Oklahoma.
The highway connects US-177 to the town of Carney, Oklahoma. It has a 25 mph (40 km/h) speed limit.
US 70 / SH-199 at Madill, OK
US-81 at South Haven, KS
