The Oregon State League was a Class D circuit which played in 1904 and was a non-classified organization in 1893-94 and an independent in 1932-39.
1893 Albany OR, Eugene OR, Oregon City OR, Salem OR
1894 Albany OR, Independence OR, Oregon City OR, Portland OR. During the season the Independence franchise moved to Salem OR.
1904 Eugene OR, Roseburg OR, Salem OR, Vancouver WA. During the season the Vancouver franchise moved to Albany OR.
1932 Albany OR, Bend OR, Eugene OR, Portland Pacific Cutfitting OR, Portland Westside OR, and Salem OR.
1933 Portland Federal OR and Portland Schapps OR entered the league; Portland Pacific Cutfitting and Portland Westside left the league
1934 Toledo entered the league; Portland Schapps left the league.
1935 No teams entered or left the league.
1936 No teams entered or left the league.
1937 Albany OR, Bend OR, Eugene OR, Portland OR, Salem, OR, Silverton OR, Toledo OR, Woodburn OR
1938 Eugene-Hills Creek OR entered the league; Salem, Toledo and Woodburn left the league.
1939 Portland-Marine Electric OR and Toledo OR entered the league.
1940 Medford, Or and Portland-Jack and Jill OR entered the league; Marine Electric and Toledo left the league.