One of Utah’s landmarks of the “land art” movement, Nancy Holt’s Sun Tunnels, will be undergoing a major conservation effort to repair decades of damage in the Great Basin Desert.

Dia Art Foundation, the New York-based nonprofit that manages such works as Sun Tunnels and Robert Smithson’s Spiral Jetty, announced Tuesday it would be doing the conservation work in early May.

It’s the first conservation work done on Sun Tunnels since Holt built it, from 1973 to 1976. Since then, the 18-foot-long concrete cylinders, aligned to the sunrise and sunset at the summer and winter solstices, have endured cracking and erosion in the extreme hot and cold weather conditions.

A team of specialized conservators, led by Rosa Lowinger, will address the weather conditions in an effort to ensure the work’s long-term conservation. The work is expected to take place on-site over 10 days.

With its experience with “land art” works, Dia has “the perfect skill set to care for that work in perpetuity,” said Whitney Tassie, senior curator and curator of modern and contemporary art at the Utah Museum of Fine Arts. “In order to do that, it helps to have local people who know the landscape.” Not just the physical landscape, but the labor force, Tassie added.

Holt oversaw some maintenance work with Utah art historian Hikmet Loe, as recently as 2010, a Dia spokeswoman said.

When Dia acquired Sun Tunnels in March 2018, said Jessica Morgan, Dia’s director, “it was imperative to make a thorough assessment of the condition of the work and ensure that any issues were addressed immediately. The conservation work we are now embarking on will secure this work for future generations.”

Holt — who died on Feb. 8, 2014, at the age of 75 — championed the “land art” movement with her husband, Robert Smithson, whose most famous work is Spiral Jetty, constructed in 1970 on the north shore of the Great Salt Lake. When Smithson died in 1973, in a plane crash while scouting locations for another art project, Holt took on the role of maintaining his legacy while building her own.

The couple bought a small parcel of land, near the ghost town of Lucin in the west desert, in 1971. She bought more land in that area, including the Sun Tunnels site, in 1975. She lived in Salt Lake City for a year in 1975, renting a studio from the late artist Lee Deffebach while completing Sun Tunnels. Holt and about 30 friends celebrated the “opening” on June 21, 1976, on the summer solstice.

“When you’re out in a place like Sun Tunnels, the desert is so vast, so overwhelming,” Holt said in a 2012 interview with The Salt Lake Tribune. “The tunnels orient you out in space and frame the view. It brings the landscape back to human scale.”

Dia acquired Sun Tunnels with support of the Holt/Smithson Foundation. It’s the first major work of “land art” by a woman to be a part of Dia’s permanent collection. Tassie said it’s exciting that Dia is collecting more work by woman artists, including Holt.

Dia acquired Spiral Jetty in 1999, a gift from Smithson’s estate, which Holt managed. Other “land art” works in Dia’s collection are Walter De Maria’s The Lightning Field in New Mexico and James Turrell’s Roden Crater near Flagstaff, Ariz.

Dia partners with the Center for Land Use Interpretation, the Holt/Smithson Foundation, and UMFA to advocate for Sun Tunnels. Dia credits Friends of Heritage Preservation, as well as Saudi billionaire Fady Jameel and the David Schwartz Foundation Inc. for supporting the conservation effort.

UMFA holds community meet-ups at Sun Tunnels periodically. The next is scheduled for Saturday, Oct. 5, from 1 p.m. to 4 p.m., at the site. Visitors are responsible for their own transportation and provisions.