Artist Bill Walker is one of those guys who always seems to be in the right place at the right time. Having met Phil Lesh, the Grateful Dead bassist and avant-garde classical composer, as a student at Nevada Southern University (now the University of Nevada, Las Vegas), Walker was invited in 1967 to make an album cover for the band’s second album, Anthem of the Sun. This experience led to an epic LSD and ayahuasca trip in the Valley of Fire outside Las Vegas over New Year’s Eve and when Walker returned to San Francisco, he painted Anthem of the Sun, complete with figures he came across in the desert.

The Anthem of the Sun painting visually demonstrates the intense innovation that happened in the psychedelic revolution, when music was electrified and LSD became central to the burst of culture that defined the 1960s. The Grateful Dead encapsulated this spirit in their music and came to be considered the most American band of all time for being at the center of the psychedelic movement and its transition from the Beat generation that preceded it.

Music history has been good to the Dead, but the art history story hasn’t been told until now. Curated by psychedelic guru Brian Chambers, 60 Years of the Grateful Dead is a retrospective exhibition that opens at the Chambers Project in Grass Valley, California, on 6 December, two days after the 60th anniversary of the band’s founding. It is the most comprehensive display of the original art from the band’s artistic history to date. “The visual vocabulary of the Dead was superior to other music groups,” Chambers said. “The Dead were a nexus and in San Francisco, there were always creatives surrounding them.”

While the show is of museum quality, gathering the works was not a typical curatorial process. Chambers owned some of it, but had to track down other works in unexpected places. The Anthem of the Sun painting was in Walker’s sister’s garage in Sacramento, where it had been stowed for years.

Other works include an original 1900 Skeleton Amidst Roses illustration by Victorian artist Edmund J Sullivan in the 1913 edition of The Rubaiyat of Omar Khayyam. It became the basis for the iconic cover of the 1971 Skull and Roses album by Mouse and Kelley. It has never been included in a Grateful Dead context like this.

Psychedelic comic master Rick Griffin has 20 works in the show, including an original pen-and-ink Hawaiian Aoxomoxoa drawing that was used for the first Dead album of the same name. “That cover was a revelation and a true key to freedom,” Roger Dean, an artist and publisher, recalled years later. “I could make my own rules, I could do what I wanted. It was my first Grateful Dead album. In fact, the first album I ever bought.” On display will also be Griffin’s acrylic circus paintings for Without a Net, Europe 90, and the original drawing from the 1967 Pow-Wow Human Be-In poster that helped kickstart the Summer of Love that year.

Featuring 20 artists who created posters and album art for the band, the exhibition is the first time these works have been brought together to tell this story. Featured artists include the “big five” of Griffin, Mouse, Alton Kelley, Victor Moscoso and Wes Wilson, along with longtime Grateful Dead collaborators including Walker, Owsley “Bear” Stanley and others who were instrumental in defining the psychedelic era.

Stanley was best known as the sound engineer for the band who helped develop the infamous “wall of sound” speaker system that itself was a work of art and another piece of the Grateful Dead’s under-appreciated gesamtkunstwerk. In the show at Chambers Project, there are five historic acid-test posters by Paul Foster that were hand-colored by Stanley, who was also famous for his Owsley LSD formula popular at the time. One poster has the first public use of the name Grateful Dead, while a poster from the 1966 Trouper’s Club acid test in Los Angeles is the only signed copy.

All of the art in the show helps tell the story of the Dead and of the US. “Psychedelic art is uniquely American, and the art of the Grateful Dead is at its beating heart. This fearless show is honest art history at its finest,” Michael Pearce, an art historian, said in the catalog.

Bill Walker had been introduced to peyote in 1962 by a friend of his uncle who was a member of the Crow Indian Tribe and a stuntman who rode horses for Hollywood. Walker and a few friends went down to Big Bend, Texas, where they filled the trunk of a Corvair with peyote, and were able to spend nearly every weekend in 1964 and 1965 eating peyote in the desert.

Walker is excited for the exhibition and to see the work of new artists. Limited-edition Grateful Dead merch will be designed by the artist Zoltron, with limited posters by AJ Masthay and Dennis Larkins. “I enjoy seeing other people’s work as much as my own,” Walker said. “There are new artists who have evolved techniques. I feel primitive.”

The show is presented in collaboration with Pact: Psychedelic Arts and Culture Trust, a non-profit run in a more philanthropic and museum-like way. The organization will host auxiliary shows in the coming months featuring the art forms that have branched off from the six decades of the Grateful Dead such as T-shirt, jewelry and glassware craft.

All of this art – new and old – helps tell the story of this incredibly influential band, even as the years go by. “The Grateful Dead is the biggest band that has ever lived,” Chambers said. “They will be around forever.”

• 60 Years of the Grateful Dead is showing on 6 December at the Chambers Project in California