Don Rhea began his career as a deputy with the Marshal’s Office in 1960. He was appointed as the Marshal of the South Judicial District in March, 1969. When the consolidation of the Marshal’s Offices occurred in 1970, Rhea was appointed to the Assistant Marshal position under the newly appointed Marshal, D. O. Wilkirson.

Don Rhea was appointed Marshal of Orange County in 1974, following the retirement of Marshal Dillard O. Wilkirson. Shortly after his appointment, Marshal Rhea provided Mutual Aid assistance to the Laguna Beach Police Department during the "Williams Canyon Love-In." In 1975, Rhea successfully fought another attempt by the Board of Supervisors to eliminate the Marshal’s Department. The Department was reorganized as a result, highlighted by the deletion of the Assistant Marshal’s position he had previously held, and two additional Captain’s positions.

Under Marshal Rhea’s leadership, the Marshal’s Office began to utilize non-sworn personnel to replace sworn officers in certain field positions. The Marshal’s Technician position was created to serve non-enforcement civil process.

Marshal Rhea retired in 1982, and was succeeded by Marshal James Byham.