Original 1st printing 20 x 14&1/8" concert poster for Quicksilver Messenger Service and Country Joe & the Fish appearing together at the Avalon Ballroom in San Francisco, CA from 5/19-21/1967.
Art by Rick Griffin, image ("Sutter's Mill") is # 62 in the Family Dog/Avalon series.
Medium flat index stock poster is in excellent (B+) condition; there is a fair amount of dried spray adhesive on the reverse and a few tiny edge dings here and there, but overall it's in very nice shape.
Great-looking 1st printing mid-'67 Rick Griffin Avalon poster.