According to the United States Census Bureau, the township has a total area of 35.4 square miles (92 km2), all land.

The main branch of the Kanaranzi Creek also flows through the northwest corner Grand Prairie Township.

The Nobles County Board liked Grand Prairie Township best, and that is why the name was chosen.

[3] Grand Prairie Township is in the extreme southwestern corner of Nobles County.

[4] The picture above is a homestead certificate issued to Alphonso Hall in 1882 and signed by President Chester A Arthur.

This was the so-called "ten-mile limit" extending for five miles (8.0 km) on either side of any rail line planned by a railroad company.

Grand Prairie Township is located in Minnesota's 1st congressional district, represented by Mankato educator Tim Walz, a Democrat.

Grand Prairie Township is represented by Nobles County Commissioner Gene Metz.