After leaving the group the first time, Marks continued to make music. In California, he found regional success with a group he formed, Dave & the Marksmen. His next project, the Moon, put out two albums. When the band folded, Marks became a classical composition student. He attended both the Berklee School of Music and the Boston Conservatory. Back in California by the '70s, Marks became a studio musician and backed other artists, among them Gary Busey, Leon Russell, and Delbert McClinton. The following decade he spent time working in blues groups alongside Buzz Clifford. Clifford had scored as a solo act in 1960 with the novelty song "Baby Sittin' Boogie."
Marks' other credits include appearances on the documentary Behind the Music from VH1 and the television series Baywatch. Entertainment Tonight and Inside Edition also featured segments on the former Beach Boy. After leaving the Beach Boys for the second time, Marks went into semi-retirement in New York state. He and his wife, Carrieann Haight, have one daughter, Jennifer Lee. ~ Linda Seida, Rovi