 When all of northern Kansas was still one numbering plan area (913), the boundary ran from west to east roughly following a path along Kansas Routes 4 and 96 from the Colorado state line eastward.The code boundary dipped along Interstate 135 in McPherson County and continued east to just north of Emporia in Lyon County along the Kansas Turnpike, and then all the way to the Missouri state line.List of NANP area codes