Jerry Garcia
Bill Kreutzmann
Bob Weir
Mickey Hart
Phil Lesh
Ron McKernan
Tom Constanten
Also Appearing
Crosby, Stills & Nash, Jefferson Airplane, and Joni Mitchell
Notes
ref: Ralph J. Gleason, "S.F. Bands Head for Hyde Park," San Francisco Chronicle, August 27, 1969, p. 35. Apparently there was a second attempt for September 20th, but that didn't pan out, either.