Michigan State Route 43 is an east-west highway in Southeastern Allegan County. It runs from the Allegan/Kalamazoo County Line, south of Plainwell, as it runs along the U.S. Rt. 131 freeway before joining Michigan State Route 89, at Plainwell. Then MI St Rt 43 follows MI St Rt 89 to the Allegan/Barry County Line east of Plainwell. MI St Rt 43 passes through the following towns in Allegan County. Plainwell
MI St Rt 43 is multi-plexed in Allegan County. U.S. Rt. 131, near Plainwell.