The township was named for the grayling fish that lived in the Au Sable River.

The Au Sable River flows west to east across the center of the township, joined by its East Branch from the north, while Lake Margrethe is in the western part of the township within Camp Grayling.

Hartwick Pines State Park is also located within Grayling Township.

As of the census[4] of 2000, there were 6,516 people, 2,420 households, and 1,802 families residing in the township.

20.7% of all households were made up of individuals, and 8.5% had someone living alone who was 65 years of age or older.