Southwestern League was an independent league in 1887, 1891, 1893, 1895, 1899, 1903, 1913, 1928), Class F (1898), Class D (1904, 1921, 1924-1926), (B 1956-1957), and a Class C 1922-1923,. also the Southwestern League was sometimes called Red River League-1898 and Oklahoma State League-1904.
1887 Fort Smith AR, Hot Springs AR, Little Rock, AR, Pine Bluff AR, Spinrgfield MO, Webb City MO
1891 Carthage MO, Ft Scott KS, Joplin MO, Parsons KS, Pittsburg KS, Webb City MO, Wier City KS
1898 Bonham TX, Denton TX, Hot Springs AR, Little Rock AR, Paris TX, Sherman TX, Shreveport LA, Texarkana TX
1903 Arkansas City, KS, Enid OK, Oklahoma City, OK, Shawnee OO
1904 Enid OK, Guthrie OK, Oklahoma City OK, Shawnee OK, During the season, the Shawnee franchise moved to Chickasha, OK then back to Shawnee.
1913 Bisbee AZ, Douglas AZ, El Paso TX, Tucson AZ
1921 Bartlesville OK, Coffeyville, KS, Independence KS, Miami OK, Muskogee OK, Parson KS, Pittsburg KS, Sapulpa OK. During the season, the Parsons franchise moved to Cushing, Ok.
1922 Hutchinson KS, Salina KS, and Topeka KS entered the league; Cushing, Miami and Pittsburg left the league.
1923 No team entered or left the league
1924 Arkansas City KS, Emporia KS, Enid OK, Eureka KS and Newton KS entered the league; Independence, Coffeyville, Blackwell left the league. During the season, the Newton franchise first moved to Blackwell, then to Ottawa and back to Newton.
1925 Bartlesville OK, Cushing OK, Enid OK and Topeka KS entered the league; Coffeyville, Emporia, Eureka, Indepenence and Newton left the league. During the season the Enid franchise moved to Shawnee, OK.
1926 Enid, OK and Ponca City, OK, entered the league; Cushing and Shawnee left the league. During the season the Ponca City franchise moved to Eureka, KS.
1928 Hamlin TX, Hollis OK, Mangum OK, San Angelo TX
1956 Ballinger TX, Carlsbad NM, Clovis NM, El Paso TX, Hobbs NM, Midland TX, Pampa TX, Plainview TX, Roswell NM, San Angelo TX
1957 Roswell and San Angelo left the league. During the season, the Midland franchise moved to Lamesa, TX and the Pampa franchise moved to San Angelo, TX.