Original 1st printing 14&1/4 x 19&7/8" concert poster for Texas psychedelic legends the 13th Floor Elevators appearing with the Sir Douglas Quintet at the Avalon Ballroom in San Francisco, CA from 9/2-3/1966.
 
 Art by Stanley Mouse and Alton Kelley, image ("Tree House") is # 24 in the Family Dog/Avalon series.
 
 Medium-thick flat vellum stock poster is in excellent (B+) there are tack holes in all four corners, along with a few VERY light handling dings hiding within the image area and a couple of tiny corner-tip/edge dings, otherwise it is an absolutely SUPERB-looking 1st printing example of this early Avalon poster featuring none other than Roky and the Elevators!