Location: Bluewater Hwy and State St, Ionia As soon as 66 joins 21, it will prepare to split to head south to Interstate 96. Location: Bluewater Hwy and Dexter Hwy, Ionia Follow 66 south to Battle Creek. Stay on 21 east for St. Johns.  S to I-96, N to MI-44  E to US-127 Bus, W … Continue reading Michigan Highway 66, MI-21 to MI-21