Riordan, who enrolled at MSU in 1940, temporarily left the university and The State News during his sophomore year to enroll in the Army. He returned in 1946 and became sports editor.
The Jackson Citizen Patriot reports that Riordan died July 6 at age 89.
After graduating, Riordan was hired by Detroit Edison's employee magazine. He later became editor and publisher of the weekly Greenwich Enterprise-Review in Ohio, and general manager of the Marysville Printing Co., which published three weeklies.
In 1957, he became part-owner of The Tecumseh Herald. After a decade, he sold his half of the paper and began teaching journalism at Hillsdale College. After one year in the classroom, he decided teaching wasn't for him.
So he went to the Jackson Citizen Patriot, which hired Riordan as picture editor. Later, he became managing editor and oversaw the introduction of an electronic newsroom. In 1978, after nine years in Jackson, he retired to become a newspaper consultant.