Mark Sivertsen is an actor who appeared in the NCIS Season 1 episode, The Immortals (episode) as Navy Commander Rivers.
He later appeared in the JAG Season 10 episode, "Whole New Ball Game".
Mark Sivertsen is an actor who appeared in the NCIS Season 1 episode, The Immortals (episode) as Navy Commander Rivers.
He later appeared in the JAG Season 10 episode, "Whole New Ball Game".