State Line Conference

Former Members
Armstrong1937-38 thru 1978-79
Armstrong-Ringsted, 1979-80 thru 1989-90
Burt1937-38 thru 1987-88
Harris-Lake Park, 1976 thru 1979 (football only)
Lakota, 1942-43 thru 1987-88
Ledyard1937-38 thru 1977-78
Lincoln Central, 1965-66 thru 1989-90
North Kossuth, 1978-79 thru 1989-90
Rake, 1958-59 thru 1978-79
Ringsted1937-38 thru 1941-42; 1958-59 thru 1978-79
Sentral, 1958-59 thru 1989-90
St. John's, Bancroft, 1980-81 thru 1988-89
Swea City, 1937-38 thru 1950-51; 1958-59 thru 1977-78
Thompson1937-38 thru 1988-89
Titonka, 1951-52 thru 1988-89
Woden-Crystal Lake, 1966-67 thru 1989-90

Membership Timeline
1990-91: Armstrong-RingstedNorth KossuthSentral-Burt, and Lincoln Central leave for the Cornbelt Conference. Woden-Crystal Lake leaves for the North Star Conference. Conference disbands.
1989-90: Titonka and Thompson consolidate with Buffalo Center-Rake-Lakota (North Iowa Conference) to form North IowaThe new school competes in the North Iowa ConferenceSt. John's, Bancroft closes. Membership decreases to 5.
1988-89: Lakota consolidates with Buffalo Center-Rake (North Iowa Conference) to form Buffalo Center-Rake-LakotaThe new school competes in the North Iowa ConferenceBurt is absorbed by Sentral, which is renamed Sentral-Burt. Membership decreases to 8.
1980-81: St. John's, Bancroft joins. Harris-Lake Park ends its football only membership. Membership increases to 10.
1979-80: Armstrong and Ringsted consolidate to form Armstrong-Ringsted. The new school remains in the league. Rake consolidates with Buffalo Center (North Iowa Conference) to form Buffalo Center-Rake. The new school competes in the North Iowa Conference. Membership decreases to 9.
1978-79: Swea City and Ledyard consolidate to form North Kossuth. The new school remains in the conference. Membership decreases to 11.
1976-77: Harris-Lake Park joins for football-only.
1966-67: Woden-Crystal Lake joins. Membership increases to 12.
1965-66: Lincoln Central joins. Membership increases to 11.
1958-59: Swea City of the Cornbelt Conference; Ringsted, Rake, and Sentral join. Membership is 10.
1951-52: Titonka joins. Swea City leaves. Membership is 6.
1942-43: Lakota joins. Ringsted leaves. Membership is 6. 
1937-38: Swea City, Armstrong, BurtRingsted, Thompson, and Ledyard form the State Line Conference. Original membership is 6.