Bonnie MacLean was born in 1939 in Philadelphia and grew up in Trenton NJ. She graduated from Penn State in 1961 with a degree in French. She moved to New York after graduating college, where she worked at the Pratt Institute and took drawing classes in the evenings. MacLean moved to San Francisco 1963, where she met Bill Graham at her office job at Allis-Chalmers where he was her boss.
Wes Wilson was the main poster artist for the Fillmore Auditorium but when he and Bill Graham had a dispute about money and Wilson quit, Bonnie MacLean stepped in. MacLean had been painting noticeboards at the auditorium in the psychedelic style, and created about thirty posters, most in 1967, many of which are considered fine examples of the developed psychedelic style.
MacLean's posters are included in many museum collections including the Museum of Modern Art in NY, the DeYoung Museum, the Fine Arts Museum of San Francisco, the Brooklyn Museum and the Smithsonian. Bonnie MacLean was married to Bill Graham from 1967-1975 and she lives as a fine artist in Pennsylvania.