Michigan State Route 66 is a north-south highway in Central Ionia County. It runs from the Ionia/Montcalm County Line, near Fenwick, to the Ionia/Eaton County Line, near Woodbury. MI St Rt 66 passes through the following town in Ionia County. Ionia
SB MI St Rt 66 at the Ionia/Montcalm County Line. SB MI St Rt 66 near Large Lake Road. SB MI St Rt 66 south of MI St Rt 44. SB MI St Rt 66 north of Ionia. SB MI St Rt 66 at west MI St Rt 21. EB MI St Rt 21/SB MI St Rt 66 at east MI St Rt 21. SB MI St Rt 66 south of Main Street in Ionia. SB MI St Rt 66 near Steele Street in Ionia. SB MI St Rt 66 at the Grand River. SB MI St Rt 66 south of Ionia. SB MI St Rt 66 near David Highway. SB MI St Rt 66 at MI St Rt 96. A BGS on WB I-96. NB MI St Rt 66 south of I-96.
