FLAGSTAFF, Ariz. (AP) _ The buildings at Petrified Forest National Park are held up as an example of modern architecture with their flat roofs, low silhouettes and large windows that opened up to the vast expanse of rainbow-colored desert.

Spanning dozens of acres, the structures provided everything the park staff and visitors would need: a gas station, restaurant, community building, maintenance shop, housing, even a two-room elementary school. The National Park Service entrusted the design to prominent architects Richard Neutra and Robert Alexander ahead of the agency’s 50th birthday, and it’s the only project of theirs still standing within the Park Service.

The National Trust for Historic Preservation recently designated the Petrified Forest compound a national treasure because of its architectural significance.

Outside national park boundaries, saving midcentury modern structures has been a chore. There are plenty of examples that have been threatened by the wrecking ball, including a Frank Lloyd Wright-designed home in Phoenix and Philip Johnson’s Glass House in New Canaan, Connecticut.

The Petrified Forest complex was on track to be demolished in 1993, but lack of funding derailed that plan and it was declared safe in 2004, said park Superintendent Brad Traver.

“I think that’s the right decision,” he said. “I agree this is an important complex. It’s unique in the National Park Service.”

The complex is visible from Interstate 40, about 25 miles east of Holbrook and beyond the trees. Visitors can also see them up close and go inside _ they house a visitor center, administrative offices, restrooms, a store and more. The design of the complex is meant to blend in with the surrounding landscape of rainbow-colored petrified wood, fossils from the dawning age of dinosaurs and petroglyphs left by American Indian tribes who once lived in eastern Arizona.

Each year about 850,000 people visit the park, which drew attention for two finds over the summer of a large ancient village of pit houses and an animal new to the park’s record. Traver said crews found what is believed to be the remains of an ancestor of both crocodiles and dinosaurs among hundreds of fossils.

Traver said he hopes to bring attention to the buildings, too, with a future exhibit that will explain its history and the plans to rehabilitate the buildings. The overall character of the complex remains intact. Some work has been done to stabilize the foundation and repair cracked concrete floor. Sewer and water lines also are planned.

The roughly 35 buildings were part of the Park Service’s Mission 66 program, a 10-year effort starting in 1956 to introduce modern architecture before the agency turned 50. Neutra finished the complex in 1965, and it was listed on the National Register of Historic Places in 2005.

Ed Soltero, an assistant vice president at Arizona State University and university architect, said Neutra paid particular attention to how the buildings at the Petrified Forest would respond to the harsh Arizona desert, and they have held up.

“Buildings are trying to capture view, trying to capture natural daylight, mitigate the heat with large overhangs, very clean lines,” he said. “Always trying to strive for the best for the occupants that were inside. You see a lot of this in this particular building.”

The designation as a national treasure comes with guidance on restoring the buildings and expertise in sustainable practices. Chris Morris, a National Trust for Historic Preservation spokeswoman, said the designation means the public will still be able to experience Neutra’s modernist architecture in person.

The complex is the only piece of Neutra’s left in the National Park Service, according to Morris. Neutra designed the 1960s Cyclorama Center at Gettysburg National Military Park in Pennsylvania. But, it was demolished in March 2013 after preservationists lost a lengthy court battle.

“There’s nowhere else to go within Arizona or within the National Park Service,” Morris said. “This is the only place within all of those public parks and monuments that you can experience a Richard Neutra design that up close and personal.”


If You Go…

PETRIFIED FOREST: http://www.nps.gov/pefo/index.htm

Associated Press writer Terry Tang contributed to this report from Phoenix.