Official promoter-issued (1966) 2nd printing 14 x 20" concert poster for the Grateful Dead appearing with Oxford Circle at the Avalon Ballroom in San Francisco, CA on 9/16-17/1966.
Art by Stanley Mouse (who has also SIGNED the piece in pencil) and Alton Kelley (central image borrowed from Edmund Sullivan), image ("Skeleton & Roses") is # 26 in the Family Dog/Avalon series.
Medium flat vellum stock poster is in good to very good (B to B/B+) condition; there are multiple pin/staple holes in each corner, a hint of toning, a bit of pen scratch on the reverse ("To Our Fearless Leader -Sincerely Yours, Denise"), light handling wear, a few stray tiny surface "chips" in the outer margin area and a few thin bends in the upper margin area, otherwise fine.
An overall fine-looking SIGNED example of the classic "Skeleton and Roses" image. Have a listen to the show (PRIMAL '66 Dead) HERE: