Janet Bishop was doing a database search for Frida Kahlo at the San Francisco Museum of Art when up popped “Untitled (Memory Drawing of Diego Rivera),” a pastel-and-charcoal image of the bearish Mexican master with his hand draped over the shoulder of his diminutive, turquoise-wearing wife, Kahlo.

It was drawn in the 1930s by Charles Stafford Duncan, a mostly forgotten Social Realist painter who was one of the left-leaning, bohemian San Francisco artists who gathered around Rivera when the great man worked on a series of landmark murals here during the Depression. Bishop, SFMOMA’s curator of painting and sculpture, knew Duncan’s name but had never seen this drawing. She fished it out of storage and gave it a gander.

Echo of Rivera

“It’s very fresh. We’re excited to show it,” says Bishop, one of the curators from SFMOMA and the Oakland Museum of California who jointly organized “Fertile Ground: Art and Community in California,” which opens Saturday at the Oakland Museum. “This was interesting not only because it captured Rivera and Kahlo, but it also seems the artist was taking on something of Rivera’s style.”

An expansive exhibition of art and ephemera drawn from the collections of both museums and other archives, the show explores four particularly creative periods in Northern California art and the convergence of personalities and social circumstances that spurred them: the 1930s era of Rivera and public art, the existential post-World War II period at the California School of Fine Arts, UC Davis during the freewheeling ’60s and ’70s, and the up-from-the-street Mission District scene of the ’90s.

The show includes everything from Rivera’s graceful sketches for his “Allegory of California” mural at the Pacific Coast Stock Exchange — and a $250 check the artist cashed from patron Albert Bender, the subject of several works here — to Kahlo paintings and photographs by Edward Weston, Dorothea Lange and Ansel Adams; paintings by Mark Rothko, Richard Diebenkorn, Wayne Thiebaud and William T. Wiley; sculptures by Deborah Butterfield and Robert Arneson; and new commissioned installations by contemporary Mission School artists such as Chris Johanson and Ruby Neri.

Letters and other artifacts, as well as historical film footage and other era-evoking elements, appear alongside the artworks, putting them in context and showing the connections between artists and their relationships with patrons and curators.

With SFMOMA closed for expansion, the curators had their pick of the permanent collection there and at the Oakland Museum, letting them tell the kind of stories that “neither of us could do as well independently,” says Bishop, who shaped the show with colleagues at SFMOMA and Oakland curators Drew Johnson and René de Guzman.

Coming together

The thesis of this show is not so much that California is an especially creative environment, Johnson says, but rather that “pockets of fertile ground like this happen throughout history, and continue to happen. The big idea of the show is people coming together at a specific place, at a specific time, influencing each other and what was going on in the larger world.”

The show opens with a scaled-down replica of “Allegory of California,” then maps Rivera’s friendships with Bay Area artists such as sculptor Ralph Stackpole and his son Peter, whose photograph of Rivera sketching the mural is on view, too, sharing space with archival footage of the 1934 San Francisco general strike, formalist photos by Weston and Imogen Cunningham, and a beautiful 1936 watercolor and gouache painting by Maynard Dixon called “Industry and the Worker.”

Pollock piece

In choosing works for the “Postwar at the California School of Fine Arts” section, Johnson couldn’t resist the opportunity to show Jackson Pollock’s iconic 1943 “Guardians of the Secret” in Oakland (it was purchased by SFMOMA with funds bequeathed by Bender). Unlike fellow Abstract Expressionists Rothko and Clyfford Still, Pollock never taught at the Russian Hill school. But his 1946 show at the museum had a huge effect on more than one generation of California artists.

One of them was Arneson, the sardonic ceramic sculptor and UC Davis professor who made many works inspired by Pollock, including “Wolf Head,” a 1989 bronze bust of Pollock’s head with a wolf on top. It’s in the Oakland collection and in the show.

So are paintings by Bay Area Figurative artist David Park, including one of the few remaining abstract pictures he made before breaking with the dominant abstract mode and bringing back the figure. He destroyed most of them. The Oakland Museum owns this one.

Free-wheeling style

The irreverent wit and embrace of pop culture that characterized the art that came out of UC Davis and environs in the ’60s and ’70s is on display in the works of Wiley, Arneson, Roy de Forest and others who were given free rein by the art department’s founding chairman, Richard L. Nelson.

Twenty years later, another vital scene sprouted in San Francisco’s Mission District, where artists such as Barry McGee, the late Margaret Kilgallen, Rigo 23 and others shaped an egalitarian, street-wise aesthetic — handmade, with humble materials — in reaction to the moneyed dot-com culture that was changing the neighborhood and city life.

“The historical context for the Mission scene was the first tech boom, the AIDS crisis and the first Iraq war,” Johnson says. “The gentrification of the Mission was a big issue then, and it is again.”

Some of the work of these artists ended up in museums, but originally, Bishop adds, “it took place in alternative galleries, on the streets, on the sides of buildings. Then the art world started to take notice, because there was a lot of energy there.”

Jesse Hamlin is a freelance writer. E-mail: sadolphson@sfchronicle.com

Fertile Ground: Oakland Museum of California, 1000 Oak St., Oakland. Saturday-April 12. $6-$15. (510) 318-8470. www.museumca.org.