Rosemarie Smith (Postmaster)
rosemarie.k.smith@usps.gov
10674 W Saint Charles Rd
Sumner, MI 48889
Sumner, MI 48889
The Sumner Post Office is located in the state of Michigan within Gratiot County. This location serves 1,322 Sumner residents with a median income of $41,083. It's estimated that approximately 2,110 packages pass through this post office each year.