Gertrude Ross Marks, 78, who won a Golden Globe award for her documentary on Mexican muralists. Born in Chicago, she grew up in Los Angeles and studied theater arts at UCLA. At 23, she became executive director of the Hollywood Theater Alliance, which produced a topical musical and political revue called "Meet the People." After a year in Los Angeles, the revue moved successfully to Broadway. Ms. Marks produced a second revue for the Hollywood Playhouse. In the late 1950s, she formed a production company, which created the award-winning feature-length documentary "Walls of Fire." The film, narrated by actor Ricardo Montalban, chronicled the work of three artists--David Alfaro Siqueiros, Diego Rivera and Jose Clemente Orozco. In addition to the Golden Globe, the documentary was nominated for an Academy Award. Ms. Marks was appointed by Mayor Tom Bradley to the citizens advisory committee for the Department of Airports. On June 7 in Westwood of heart failure.