[5] According to the 2010 census, the township has a total area of 47.66 square miles (123.4 km2), all land.

U.S. Route 41 runs along a portion of the township's eastern border, starting at the northeastern corner and going south for about 1 mile (1.6 km) before veering to the east.

[7] Indiana State Road 352 leaves State Road 26 at the western border and runs north for about 1 mile (1.6 km) before leaving the township (and the county) on its way through the small town of Ambia in Benton County.

Most of Prairie township lies in the Benton Community School Corporation, and the southern portion of Prairie Township is part of the Metropolitan School District of Warren County.

[9] Prairie Township has a trustee who administers rural fire protection and ambulance service, provides relief to the poor, manages cemetery care, and performs farm assessment, among other duties.