Missouri Secondary State Route A is a north-south highway in Southwestern Knox County. It runs from Missouri State Route 6 to Missouri State Route 156. MO Sec St Rt A does not pass through any towns in Knox County. MO Sec St Rt A is not multi-plexed in Knox County. MO Sec St Rt A intersects the following highways in Knox County. Missouri State Route 6, near Hurdland.