U.S. Federal Route 81 is one of the main north-south highways in Sumner County. This highway runs from the Oklahoma/Kansas State Line to the Sumner/Sedgwick County Line. U.S. Rt. 81 passes through the following towns in Sumner County. Caldwell South Haven Wellington U.S. Rt. 81 is not multi-plexed in Sumner County. U.S. Rt. 81 intersects the following highways in Sumner County. Kansas State Route 49, at Caldwell. U.S. Rt. 166, at South Haven. U.S. Rt. 177, at South Haven. U.S. Rt. 160, at Wellington. Kansas State Route 55, near Belle Plaine. Kansas State Route 53, near Peck.