Since Iowa is the only state in the nation that maintains separate governing bodies for boys' and girls' athletics, the classifications are different for each gender. The Iowa High School Athletic Association is divided into classes 4A, 3A, 2A, and 1A while the Iowa Girls High School Athletic Union is divided into classes 5A, 4A, 3A, 2A, and 1A. Five of the eight members of the MRAC conference are part of the largest class for boy boys and girls athletics; the exceptions - Bishop Heelan Catholic, Le Mars Community, and Sergeant-Bluff Luton, are part of Class 3A for boys and either class 4A or 3A for girls athletics.
History
For most of their athletics histories, the schools of the Missouri River Activities Conference were in other conferences. Beginning in the early 1970s, Sioux City schools began to compete with schools in Sioux Falls, South Dakota, as a members of the boys-only Sioux Interstate Conference. In the late 1970s, the Sioux Delta Conference was formed between the Sioux City schools, LeMars Community, and Hull Western Christian to facilitate girls' athletic competition. A separate intrastate conference was necessary because the SouthDakota High School Athletic Association conducted its girls' basketball tournament in the fall and volleyball tournament in the winter, opposite of many bordering states. From the 1920s to the 1950s C.B. Abraham Lincoln and Sioux City East competed with three Omaha high schools and Lincoln High in the Missouri Valley Conference. Sioux City Central, which closed in 1975, was also a member. In spring 1997, the South Dakota High School Activities Association effectively closed its borders to interstate athletic competition, forcing the dissolution of the Sioux Interstate Conference. The Sioux Delta Conference also dissolved that spring as both LeMars Community and Hull Western Christian had by this time found homes in the Lakes Conference, leaving the four Sioux City schools out in the cold. The Council Bluffs schools, meanwhile, were once part of the Omaha metro league which included numerous schools in Nebraska. After bowing out of the Omaha metro league, the two schools became charter members of the River Cities Conference, a league that included Nebraska schools such as Beatrice, Ralston, South Sioux City, Omaha Gross, Omaha Roncalli, and Omaha Skutt. With few options due to their size as 4A football schools, the Sioux City schools and Heelan sought out and were denied membership in both the Central Iowa Metro League and the River Cities Conference. Undaunted, the schools petitioned the Iowa Department of Education for placement in an athletic conference. As a result of those proceedings, the Missouri River Conference was formed to meet the needs of the Sioux City schools, pulling the Council Bluffs schools out of the River Cities Conference to complete the six-school lineup. In 2010, Sergeant Bluff-Luton, a founding member of the War Eagle Conference in 1979, began competing as the league's seventh school. LeMars Community announced in February 2018 that it would be joining the conference as the eighth member for the 2019-2020 academic year, leaving the Lakes Conference. Lewis Central and Glenwood were also invited, but declined, opting to continue competing in the Hawkeye Ten Conference.