Original 1st printing 23 x 17&1/2" event poster for the Seattle HELIX (underground paper)-sponsored "Chief Seattle Flower Potlatch and Isness-in", a single day gathering of the hippie tribes/"be-in", held at Volunteer Park in Seattle on 4/30/1967.
Art by Maryl Clemmens, medium-thick flat vellum stock poster is in BEAUTIFUL near mint (A- to A-/B+) condition; aside from a touch of curl to the paper and a whisper of edge/corner wear (a tiny bend or two around the outer edges), this example is just about as clean as they come.
Absolutely GORGEOUS split-fountain-colors on this piece! One of the more obscure (and cool) PNW event posters that I have come across... VERY, VERY cool.