"Pacific Standard Time: Art in L.A., 1945–1980," a monumental exhibition opening in part this weekend at the Getty Center, means to remind the world that Los Angeles was an unofficial center of art production in the postwar United States. "Many of the major cultural institutions, such as the Getty, the Hammer Museum and the Museum of Contemporary Art (MOCA) have existed only since the 1980s," Andrew Perchuk, the deputy director of the Getty Research Institute and the curator of "Crosscurrents in L.A. Painting and Sculpture, 1950–1970," one of four exhibitions in the program, told A.i.A. "There were great artists making art here, there just wasn't any support for them."

Perchuk, a New York native and graduate of Columbia University, explained: "When I first came to Los Angeles in the 1980s, many artists here were moving to New York. Now, the traffic is going in the reverse direction." "Crosscurrents," which chronicles the rise of the art scene in Los Angeles, includes painting and sculpture produced before 1970. It consists of 79 works on loan from all over the world by artists including John Baldessari, Vija Celmins, Richard Diebenkorn, Judy Chicago, David Hockney, Bruce Nauman and Ed Ruscha.

Many of the works are art historical gems, previously unknown or lost to the public record. An untitled 1966 sculpture by assemblage artist Noah Purifoy was constructed from detritus found on the streets after the Watts Riots of 1965. The piece had traveled for four years around the country in an exhibition, "66 Signs of Neon," organized by Purifoy and artist Judson Powell, on the aftermath of the uprising. When the works returned to Los Angeles, there was no room for storage, so most of them were thrown away. A few were acquired by collectors during the tour of the show. "One of my students found Purifoy's untitled work in a private collection in Las Vegas," Perchuk said.

In his heyday, Ronald Davis showed with Leo Castelli in New York and John Kasmin in London, but he's largely been forgotten. His two geometric abstractions in "Crosscurrents," Vector (1968) and Black Tear (1969), were bought by the Tate in London in 1968, and haven't been seen since. Another curiosity discovered by Perchuk was a work by Norman Zammitt, who grew up on a Native American reservation, and worked to develop notions of color theory with scientists at Cal Tech. Perchuk found one of his paintings, North Wall (1976), hanging on the ceiling in the bedroom of a crowded apartment in the San Fernando Valley. In the exhibition at the Getty Center, it hangs the traditional way.

It's clear that Perchuk has a special fondness for the work of DeWain Valentine, a Minimalist sculptor who made simple, large-scale geometric forms from glass and cast polyester resin. Red Concave Circle (1970) features in "Crosscurrents," while the Getty has also staged "From Start to Finish: DeWain Valentine's Gray Column," an exhibition that narrates through film, photographs and the object itself the creation of Gray Column (1975–6), a 12-foot-high, 8-foot-wide, 3,500-pound polyester resin work by Valentine that has never before been seen by the public. "He only made three of these in his career," Perchuk explained to A.i.A. "They strained the limits of what was technically possible with resin. They are incredible achievements."

A Bigger Splash, 1967, David Hockney. Acrylic on canvas. 96 x 96 in. Tate: Purchased 1981. © David Hockney. Image: © Tate, London 2010
Gray Column, 1975-76, De Wain Valentine. Polyester resin. 140 x 87 1/2 x 9 1/2 in. Lent by De Wain Valentine. Artwork © De Wain Valentine