The beginning of the Sheriff's Department's own training program and the Sheriff's Training Center is also the beginning of the Riverside Sheriffs' Association.

In the late 1930's, former Sheriff Carl F. Rayburn and his Undersheriff, Steve Lynch, formed a special team which struggled to professionalize law enforcement in Riverside County by conducting formal classroom and firearms training with the cooperation of the FBI.

Because of the refusal of the County of Riverside to provide a training facility for Deputy Sheriffs, expend county monies for training, or reload ammunition for practice firing, Sheriff Rayburn formed the Deputies under a non-profit corporation in 1943, for the purpose of accepting a gift of property from a local property owner who was sympathetic to the needs for a training facility. The corporation was entitled "Riverside County Sheriff's Training Center." Off-duty Deputies leveled the land, built a kitchen and emergency generator building, and moved in surplus army barracks for classrooms. A firing range was constructed with movable targets, and a firing shed and ammunition reloading building were equipped.

During the beginning years, revenue from dues, reloaded ammunition sales, commissary sales, barbecue dinners, rodeos and motorcycle races, plus an abundance of donated time by the membership, allowed the training association to remain financially stable.

In 1953, the Riverside County Sheriff's Training Center Corporation found itself over-burdened with maintenance costs. The members realized they were unable to continue to operate the Training Center, let alone provide financing for necessary improvements and needed expansion. The members agreed to deed the facility to the County, in return for budget allowances to maintain and expand the facility, provide law enforcement training, and furnish reloads for firearms practice.

With the deeding of the training facility, it appeared that the need for a non-profit corporation no longer existed; and the corporate registration was allowed to lapse. In 1954, the Riverside County Sheriff's Training Center, Inc. was declared defunct and was replaced with an unincorporated association of Sheriff's employees called the "Sheriff's Relief Association."

The association joined PORAC in 1961 and was re-incorporated on July 31, 1968. It registered as a non-profit association of local employees and was renamed Riverside Sheriff's Association.

The Articles of Incorporation were amended on November 18, 1970, to include, as an additional objective of the association, that RSA would represent its members in their employment relations with the County of Riverside. This amendment was required due to the passage of the Meyers-Milias-Brown Act, which gave public employees the right to band together and collectively bargain for the terms of their wages, benefits and working conditions.

During 1976, criticisms concerning the "at-large" elections of the Board of Directors prompted extensive committee efforts, which produced a complete re-drafting of the Bylaws. Chapters were established within the Association, each represented by a member of the Board of Directors.

The Bylaws were again amended by the membership, effective December 3, 1981, to change the way the Association operated and to resolve conflicting language.

The Articles of Incorporation were again amended on May 7, 1982, to identify the primary purpose of RSA as a labor organization within the meaning of Section 2301a of the California Revenue and Taxation Code. The association changed from a "non-profit corporation" to a "not-for-profit labor organization."

Several additional amendments to the Bylaws have taken place since, as follows:

1983: Major restructuring with the creation of Committees to help operate the Association.

1989: Authorized full time release of the president.

1998: Authority of the Board of Directors was expanded to include the power to re-organize itself as needed.