Much of the Lower Sioux Indian Reservation is located in Sherman Township.

As of the census[1] of 2000, there were 301 people, 107 households, and 81 families residing in the township.

The racial makeup of the township was 54.82% White, 43.19% Native American, and 1.99% from two or more races.

19.6% of all households were made up of individuals, and 9.3% had someone living alone who was 65 years of age or older.

About 4.8% of families and 9.6% of the population were below the poverty line, including 9.0% of those under the age of eighteen and 8.6% of those 65 or over.