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 near mint to excellent (A-/B+ to B+) there is a TINY 1/8" nip tear in the upper right margin, along with a sliver of toning along the extreme upper left margin, a tiny bend in the top left corner tip, a nearly-invisible thin vertical bend along the lower left margin, a tiny bend in the top right corner tip and a soft handling ding or two hiding within the image area, otherwise it is a nearly-perfect example of this early Avalon poster featuring none other than Roky and the Elevators!