K-99 is a state highway in the U.S. state of Kansas. The highway runs 234.473 miles (377.348 km) from Oklahoma State Highway 99 (SH-99) at the Oklahoma state line near Chautauqua north to Nebraska Highway 99 (N-99) at the Nebraska state line in Summerfield. K-99 connects Emporia with several smaller county seats to the south and north, including Sedan, Howard, Eureka, Alma, and Westmoreland while passing through the Flint Hills of eastern Kansas.