This poster is the LP illustration from Golden Dawn's Album Power Plant. They were based in Austin, Texas and were friends of Rocky Erickson of the 13 Floor Elevators. I recently corresponded with one of the band members and found out they still are making music together and have just released a new CD. The poster glows great under a blacklight!
East Totem West was one of the most significant poster companies from the late 60's. Based in San Francisco, their posters are sublime slices of psychedelia and very rare now. consider also purchasing the highly recommended book "The White Rabbit And Other Tales" by Alan Bisbort, which all of ETW's posters are featured in.