A 74-foot-wide, 10-panel fresco painted by Diego Rivera for the 1940 Golden Gate International Exposition on Treasure Island, which has lived in a theater building at City College since the early 1960s, has just been very carefully relocated to SFMOMA ahead of a big Rivera retrospective opening next year.

A project manager with the museum describes the delicate move as akin to transporting a "70-foot eggshell" across town, but it has reportedly arrived unscathed. As the New York Times reports, the operation involved a feasibility study, and extensive preparatory work by engineers from Universidad Nacional Autónoma de México’s multidisciplinary design center, "which has been known to tackle the near-impossible." It also involved a specially equipped truck with custom shock absorbers to make seven trips across town traveling five miles per hour.

Rivera painted the work, titled "Pan American Unity," live in front of thousands of spectators at the world's fair in 1940, with the intention that it would be moved and live permanently at City College. With the move in mind, he painted it in 10 pieces on separate steel-framed panels, with limestone plaster as the base.

City College took its time installing it, initially intending it to be the centerpiece of a new library whose construction was delayed by World War II. The fresco stayed in storage until 1961, when it was installed a cramped space in what's now known as the Diego Rivera Theater — and now, as the Times notes, City College has new plans for a theater building that will better showcase the fresco, although construction on that has not yet begun.

The fresco's handlers at City College clearly never intended to move the piece again, and de-installing it from the walls of the theater was a unique challenge.

The panels have been installed on a 74-foot-wide, 28-foot-high steel frame in SFMOMA's street-level, publicly accessible gallery space along Howard Street — the same entrance gallery that formerly housed a massive Richard Serra piece when the museum reopened, and, more recently, the digital mural titled "The Chronicles of San Francisco" by French artist JR.

"Pan American Unity," the complete title of which is, "The Marriage of the Artistic Expression of the North and of the South on This Continent," will now be the largest work on display at SFMOMA's 2022 exhibition, Diego Rivera's America. The mural features American inventors and industrialists like Samuel Morse and Robert Fulton (both of whom were also painters), dictators, U.S. presidents, movie actors, Mexican artisans, and Rivera inserted himself and wife Frida Kahlo. Charlie Chaplin is depicted multiple times in one section, celebrated for his work satirizing Adolf Hitler in The Great Dictator.

SFMOMA Director Neal Benezra calls the piece "Rivera’s painterly plea for a kind of unity of the Americas."

He adds, "We’re living in a time of tremendous resurgent nationalism around the world, and this is an anti-nationalist way of looking at things."

The piece will now be visible to the public when the gallery reopens on June 28, and will remain on view through at least 2023.

A self-appointed expert on the piece at City College, 74-year-old retired lab manager Will Maynez, tells the Times that it's been his life's dream for more people to get to see and appreciate "Pan American Unity" — after decades of it being tucked in a remote location where only Rivera-hunting tourists came to seek it out. With the piece, Maynez says, "Diego was building a metaphoric bridge between the Mexican culture and the tech culture of the United States."

Much like some of Rivera's other monumental mural work, like his 1931 piece commissioned by the San Francisco Art Institute, "The Making of a Fresco Showing the Building of a City," the piece needs to be seen up close and in person. Rivera also painted a third mural in SF during that decade, at City Club downtown.

The full Rivera retrospective at SFMOMA does not yet have an opening date next year.

Top image: Banco de Mexico Diego Rivera & Frida Kahlo Museums Trust, Mexico D.F./Artist Rights Society (ARS), New York, via City College of San Francisco