Alan Marshall grew up in Northeastern Oklahoma, graduating from Bacone Indian School. He attended the University of New Mexico, graduating with a degree in Theatre Arts in 1962. The following year he received a scholarship to study with Paul Baker at the Dallas Theatre Center in Dallas, Texas. After leaving Dallas, he was awarded a Fellowship in Theatre Design at City University of New York, Brooklyn College, where he studied Scene and Costume Design with the late Eldon Elder.
Marshall became resident Playwright at the Inner City Cultural Center in Los Angeles, California, where his play Eagle Boy was given a world premier in the late 1960's. Awarded a Ford Foundation grant, he studied and wrote throughout the Southwest for two years.
Returning to New Mexico, Marshall, in collaboration with his wife Nancy and the late Santa Fe Galloway, founded the New Playwrights Theatre in 1970 at the old Rodey Theatre on the UNM campus. The following year Marshall accepted the Chairmanship of the Department of Fine Arts and New Mexico Institute of Technology (NMIMT) where he taught Theatre Arts, Painting, Drawing and Film Aesthetics.
In the 1980's and 1990's Marshall worked in California and New Mexico in film and TV His Come Sweet Death, a short film inspired by J.S. Bach's musical composition, was awarded Outstanding Recognition at the Galveston on the Strand Film Festival. In addition his play, Eagle Boy was accepted into the permanent collection of the Langston Hughes Memorial Library in Los Angeles, California.
Marshall has four children and he and his wife Nancy reside in Bosque Farms, where he has his art studio.