In 1954, Simpson co-founded the Six Gallery at 3119 Fillmore Street in San Francisco alongside Wally Hedrick, a neo-expressionist painter and integral member of the Beat movement ; Deborah Remington, an abstract artist known for hard-edge painting abstraction; Jack Ryan, a poet; Hayward King, an artist who became the director of the Richmond Art Center, and Jack Spicer, a poet and faculty member at the San Francisco Art Institute. Before it was turned into one of the inaugural student-run cooperative galleries in the area, the space had been an auto-repair shop. Herb Caen wrote in the San Francisco Examiner on September 26, 1954 that the Six Gallery was "sponsored by six people interested in art, music, poetry, integrity and other worthwhile things." Many well-known artists, including Joan Brown and Manuel Neri, held their first one-person shows at the Six Gallery. On October 7, 1955, Allen Ginsberg read his famous poem, "Howl" publicly for the first time at a reading at the Six Gallery."Howl’s" future publisher Lawrence Ferlinghetti, the poet Michael McClure, and Jack Kerouac were in the audience, but Simpson, home sleeping after a night shift at his gas station job, missed the reading. The Six Gallery closed in 1957.