Dennis Oppenheim, a venerated American artist known for a remarkably protean corpus of work, ranging from Body and Land Art to more recent monumental public sculptures, passed away on Saturday of liver cancer at the age of 72. Oppenheim's Los Angeles dealer and friend Thomas Solomon confirmed the news to the Milwaukee Journal Sentinel.

Oppenheim was born in 1938 in Electric City, Washington, studying at the California College of the Arts and Stanford University, before moving to New York in 1966, at the height of the Conceptual art movement. He remained based in the city for the rest of his life. His long career is notable for his restless, constant quest to reject convention — including expectations he had set up for his own art.

View Slideshow: Dennis Oppenheim, Restless Artistic Innovator, Passes Away at 72

"I have never been able to be what they call a signature artist," he said in one of his final interviews, in the Las Vegas publication Desert Companion. "Most of my work comes from ideas. I can usually do only a few versions of each idea. Land Art and Body Art were particularly strong concepts which allowed for a lot of permutations. But nevertheless, I found myself wanting to move onward into something else."

Oppenheim began his career with ephemeral interventions into the landscape, like "Landslide" (1968), which involved adding a configuration of angled boards around the Long Island Expressway, and "Gallery Transplant" (1969), for which he etched the dimensions of a gallery in the snow — a phantom space that disappeared as the temperature changed.

On his Web site, Oppenheim summed up the important stages in his subsequent work in the following way: From 1970 to 1974, he worked with his own body "to challenge the self," creating performances like "Reading Position for Second Degree Burn" (1970), for which he lay in the sun for five hours with nothing but an open book on his chest; in 1981, Oppenheim began his so-called "machine pieces," complex, space-filling contraptions he described as metaphors for the unpredictable nature of the artistic process (one of these works, involving live fireworks, went berserk at a Soho gallery in 1982, causing firetrucks to be called); after the mid-1980s, he focused on the "transformation of everyday objects in art" in works like "Chair/Pool" (1996), a giant chair made from pipes and steel mesh, containing two tons of water, made for a sculpture park in Lithuania.

This last series seamlessly morphed into the mode of art-making that would preoccupy the last decades of Oppenheim's life: large-scale public artworks, often combining aspects of architecture with aspects of sculpture. Often, these works, which put Oppenheim's iconoclastic sensibility on very public display, proved controversial. Most notoriously, his "Device to Root Out Evil" — a church turned upside-down originally seen at the 1997 Venice Biennale — had difficulty finding a permanent location, being deemed too controversial for locations in New York and Stanford, ending up for a time in a Vancouver park before being moved again because the monumental sculpture blocked views.