For the past three years, visitors to Dinosaur National Monument, which straddles the border of Utah and Colorado, have been unable to enter one of the park’s top attractions: the Quarry Visitor Center.
 
Designed by the San Francisco firm of Anshen and Allen and completed in 1958, the Modernist structure features a round concrete-block administrative building with a sinuous ramp leading to a glass-walled exhibit hall, which contains a quarry of Jurassic-period dinosaur bones and other fossils. But the visitor center was built on unstable bentonite clay, causing it to shift and sway. Photographs on the monument’s Web site show uneven door frames, cracked exterior walls, and detached support columns. In 2006, structural engineers deemed the landmark unsafe and recommended that it be closed.
 
Now, due in part to $13.1 million in federal stimulus funds, portions of the visitor center will be demolished and a new building, designed by Barker Rinker Seacat Architecture, of Denver, will be constructed nearby. Another Colorado firm, Andrews & Anderson Architects, of Golden, will renovate and reinforce the exhibit hall, with its distinctive butterfly roof, that encloses the quarry.
 
The Quarry Visitor Center was constructed as part of the National Park Service’s Mission 66 program, which during the late 1950s and early 1960s resulted in a number of Modernist-style visitor centers. In recent years, preservationists have sought to prevent the demolition or alternation of some Mission 66 buildings, most notably the Richard Neutra-designed Cyclorama building in Pennsylvania’s Gettysburg National Military Park.
 
Only a handful of Mission 66 structures, including the Quarry Visitor Center, have been designated as National Historic Landmarks, according to architectural historian Christine French, director of the National Trust for Historic Preservation’s modernism and recent past initiative. But even landmark status isn’t enough to preserve a building deemed structurally unsound, as is the case with the Quarry Visitor Center. “It was too far gone and only getting worse,” says Chris Hansen, a preservation specialist with the Utah State Historic Preservation Office.
 
Monument superintendent Mary Risser says the Park Service had hoped to preserve the entire visitor center, but she’s pleased the exhibit hall will be renovated. Mostly, she’s glad the public—by 2011, if all goes according to schedule—will once again be able to see the park’s famous quarry, discovered in 1909 by paleontologist Earl Douglass. Since 2006, visitation to the national monument has dropped by one-third. “It’s really been tough having it closed for the last three years,” she says.