Located in the northeastern part of the county, it borders the following townships: No municipalities are located in Mason Township.

Established before 1873, Arabia is a populated place in the township.

[5] Yarico is also a populated place in the township.

[7] The township is governed by a three-member board of trustees, who are elected in November of odd-numbered years to a four-year term beginning on the following January 1.

There is also an elected township fiscal officer,[8] who serves a four-year term beginning on April 1 of the year after the election, which is held in November of the year before the presidential election.