Illinois State Route 37 is the main north-south highway in Central Marion County. This runs along the eastside of Interstate 57. IL St Rt 37 passes through the following towns in Marion County. Kinmundy Alma Salem IL St Rt 37 is not multi-plexed in Marion County. IL St Rt 37 intersects the following highways in Marion County. U.S. Rt. 50, at Salem.