The population was 236 at the 2020 census, which makes it the county's least-populated municipality.

It was named after the southern branch of the Au Sable River, which flows through the township.

23.6% of all households were made up of individuals, and 9.1% had someone living alone who was 65 years of age or older.

About 17.3% of families and 23.9% of the population were below the poverty line, including 40.0% of those under the age of eighteen and 20.0% of those 65 or over.

[8] The township was once home to the main campus of Kirtland Community College, which was founded in 1966.