The Class D level league had franchises based in Illinois and Iowa.
The Ottumwa Snappers franchise won league championships in 1904 and 1905.
Seven of the eight 1907 Iowa State League teams formed the Central Association in 1908.
Estherville defeated Fort Dodge in the league playoffs to claim the championship.
1907 Iowa State League schedule 1912 Iowa State League schedule Clear Lake folded July 14 Playoffs: Estherville 4 games, Fort Dodge 1.