The concert footage in the film is taken from the Grateful Dead's five night stand at Winterland in San Francisco, from October 16-20, 1974. The final show of this run (October 20) was billed as "The Last One", as the Dead were set to begin a hiatus of unspecified time after the completion of these shows. (They would go on to not tour in 1975, and return to the road in 1976.)
The Winterland Auditorium where the Dead recorded these shows, is the same venue where The Band staged "The Last Waltz" two years later, it would later be demolished.
The "Sandy... tavelling in from New York [For the concert]" referred to by the Hells Angels is more than likely Sandy Alexander, founder if the New York City chapter of the motorcycle club.
Initially budgeted at $125,000, the addition of an animated sequence helped push that figure to $600,000. Jerry Garcia called the efforts "two years of incredible doubt, crisis after crisis." The other band members called it "Jerry's jerk-off."