Erdahl Township was organized in 1877, and supposedly named after "a district in Norway".
As of the census of 2000, there were 343 people, 132 households, and 107 families residing in the township. The population density was 10.1 people per square mile (3.9/km²). There were 186 housing units at an average density of 5.5/sq mi (2.1/km²). The racial makeup of the township was 99.13% White, 0.29% Native American, and 0.58% from two or more races.
