A child of the Northeast, Holt described her first exploration of the West, around Las Vegas in 1968 with Smithson and Heizer, as transformative in her life as an artist; during the visit, she said, she did not sleep for four days.
"It seemed to me that I had this Western space that had been within me," she said many years later. "That was my inner reality. I was experiencing it on the outside, simultaneously with my spaciousness within. I felt at one."
She began her career writing concrete poetry and making photographs, films and videos. From the beginning she was interested in how perception is shaped, and she used the mediums of lenses, viewfinders and other structures to alter the way urban space, land and the firmament are experienced over time.
"I wanted to bring the vast space of the desert back down to human scale," she once wrote about "Sun Tunnels."
Throughout her career Holt was underrecognized, in part because her best work — "Dark Star Park," an installation on a once-blighted site in Arlington, Va.; "Sky Mound," a partly completed earth sculpture and park made from a landfill in the New Jersey Meadowlands; "Up and Under," a sinuous tunnel-and-berm construction outside a small city in Finland — could not be shown in museums or galleries. And she held a fairly dim view of the traditional art world anyway.
"If work hangs in a gallery or museum," she once said, "the art gets made for the spaces that were made to enclose art. They isolate objects, detach them from the world."
Holt also devoted considerable time to protecting the legacy of Smithson, who died in a plane crash in Amarillo, Texas, in 1973 while surveying a site for one of his earth works.
In 2008 she helped rally opposition to a plan for exploratory drilling near the site of Smithson's greatest work, "Spiral Jetty," a huge counterclockwise curlicue of black basalt rock that juts into the Great Salt Lake in rural Utah. After Smithson's death, Holt never remarried. She told one interviewer, "My art was enough for me."
No immediate family members survive.
Nancy Holt was born on April 5, 1938, in Worcester, Mass. An only child, she was raised in New Jersey, where her father worked as a chemical engineer and her mother was a homemaker.
She studied biology at Tufts University and then moved to New York, where she quickly became involved with a group of prominent Minimalist and post-Minimalist artists including Carl Andre, Sol Lewitt, Eva Hesse, Joan Jonas and Richard Serra. (She collaborated with Serra in 1974 on "Boomerang," in which he videotaped her listening to her own voice echoing back into a pair of headphones after a time lag, as she described the disorienting experience.)
She and Smithson had bought a small piece of land in Utah, and in 1974 she bought more: 40 acres for $1,600 in the Great Basin Desert, where she set about building "Sun Tunnels." As she wrote later, installing the culverts — each weighing 22 tons — and documenting the process, required the help of "2 engineers, 1 astrophysicist, 1 astronomer, 1 surveyor and his assistant, 1 road grader, 2 dump truck operators, 1 carpenter, 3 ditch diggers, 1 concrete mixing truck operator, 1 concrete foreman, 10 concrete pipe company workers, 2 core-drillers, 4 truck drivers, 1 crane operator, 1 rigger, 2 cameramen, 2 soundmen, 1 helicopter pilot, and 4 photography lab workers."
"In making the arrangements and contracting out the work," she wrote, "I became more extended into the world than I've ever been before."
Over the years, the work has attracted a variety of pilgrims: art lovers who camp out to see the sunrise perfectly aligned with the tunnels at solstice; latter-day pagans who come for the same reason; Burning Man-type celebrants who used the tunnels as a gathering place; hunters who use them for shooting practice. Occasionally, Holt would drive back to the site and invite observers to meet her for a free-form talk and viewing experience.
The first retrospective of her work, "Nancy Holt: Sightlines," opened in 2010 at the Miriam and Ira D. Wallach Art Gallery at Columbia University and traveled to several other venues in the United States and Europe. In a public talk in Santa Fe, N.M., during the run of the retrospective, she described the struggle of pursuing an art career largely out of doors, and decidedly on her own terms.
"It was painful, because I had no product," she said. "And especially a woman in the art world at that time, you had to have something to show." She added: "I was just being. I was emphasizing being over becoming. And in the art world it's a hard stance."