Hartwick Pines State Park 
Route 3
Grayling, MI 49738
517-348-7068

Hartwick Pines State Park, with an area of nearly 10,000 acres making it the largest state park in the lower peninsula and the fifth largest park state-wide, is located just north of Grayling, off I-75. The park is open daily from 8 a.m. to 10 p.m.