Classified as a major collector road,[2] the southern K-8 is a continuation of SH-8, linking northern Oklahoma to the town of Kiowa.

[3] Approximately halfway between the state line and the northern terminus, the highway crosses a single track originally belonging to the Atchison, Topeka and Santa Fe Railway, which is now part of BNSF Railway's Kansas Division.

[4][5] The northern K-8, also classified as a major collector road,[6] begins at an intersection with US-36 near Athol, traveling north through rural farmland in northern Smith County.

The highway terminates at the Nebraska state line, where the roadway continues as N-10.

US-281 has replaced the former statewide K-8 as the primary link between Oklahoma and Nebraska.