Colorado State League was an unclassified organization during the following years: 1885, 1889-1891 that was based in Colorado.
1885 Colorado Springs, Denver, Leadville, Pueblo
1889 Aspen, Colorado Springs, Denver, Leadville, Pueblo
1895 Aspen, Gillette, Leadville, Pueblo
1896 Colorado Springs and Denver entered the league.
1897 Fort Collins, Glenwood Springs and Louisville entered the league; Colorado Springs and Gillette left the league.
1898 Louisville left the league.
1908 Copper Creek, Glenwood Springs, La Junta, Pueblo
1909 Colorado Springs, Denver A, Denver B, Pueblo