 Most of the city of Eden Valley is located in Manannah Township

Manannah Township was organized in 1857, and named after Manannah, Minnesota.According to the United States Census Bureau, the township has a total area of 38.6 square miles (99.9 km²), of which 38.5 square miles (99.6 km²) is land and 0.1 square miles (0.3 km²) (0.31%) is water.Manannah Township is located in Township 121 North of the Arkansas Base Line and Range 31 West of the 5th Principal Meridian.