Riverside Junior High opened on September 6, 1950 for grades 7 through 9. The original proposal was for twenty-five classrooms. The bid was for $479,615. The actual cost was $547,545. The school was built to hold 800 students. The first semester the enrollment was 960. Three classes met in the auditorium. By 1954 six two room-cottages were added outside. In 1956 twenty new classrooms were added. The offices of the vice-principal, dean of girls, and nurse were enlarged. Another counselor's office and laboratories for science, journalism, and reading were added. The boys' PE area and the cafeteria were also enlarged.
The faculty increased from thirty-six to forty-three. In addition to English, Math, and Social Studies, students could also take Latin, Spanish, Speech, Art, Home Economics, Industrial Arts, Band, Orchestra and Choir. Student organizations included Student Council, National Junior Honor Society, Junior Red Cross, Y-Teens, Latina Sodalitas, Slide Rule Club, Eaglet Aides, Operator's Club, Bluettes, and Cheerleaders.
During this time period the PTA made many contributions. Some examples included slide projectors, film strips, chairs, money for banquets, a fan for every classroom, ice water fountains, evaporative coolers for the cafeteria, assistance in furnishing football blocking dummies, and a basketball scoreboard. The Lions Club also assisted in providing money for the basketball score board.
In the 1970's the ninth grade was moved to the high school and the sixth grade moved to what became Riverside Middle School. Student organizations now include Student Council, National Junior Honor Society, Chess Club, Science Club, Culture Club and Art Club.
In 1987 Riverside joined the Adopt-A-School program when the school was adopted by The Worthington Hotel. Through the years Riverside and The Worthington Hotel have won several awards for their outstanding partnership. The parent organization has previously provided teachers with money to purchase supplies for the classroom, the school marquee and sponsored a yearbook, among other projects.
In 2001 a new addition was constructed to reflect the growing needs of students in the community. Included were new front offices, library, science labs, and classrooms. In addition in the location that previously included the office were renovated into two new classrooms. In what was the library now contains a computer lab and classroom. New programs to RMS include Advancement Via Individual Determination (A.V.I.D.), added in 1999, Communities In School, added in 2000, and Reaching Our Potential in Education (R.O.P.E.), added in 2001. Also beginning with the 2001-2002 school year all classrooms are Internet capable. Cheerleading returned to Riverside in the 1999-2000 school year. In 2008-2009 the bond program brought Promethean interactive white boards to the classrooms.