Tennessee's Oak Ridge National Laboratory was such a well-kept secret during World War II that most Americans still don't know it sits off one of busiest highways in the South.
Streams of vacationers whiz by the site that enriched uranium for America's first atomic bombs on their way to Great Smoky Mountains National Park — the most popular in the nation, just south of Knoxville off Interstate 40.
But a spotlight might soon shine on the Oak Ridge lab and two other largely forgotten Manhattan Project sites on the approach of the 70th anniversary of the general order that established it. The Obama administration is supporting bipartisan legislation in Congress that would designate major sites in Oak Ridge; Hanford, Wash.; and Los Alamos, N.M., as national parks, paving the way for wider exposure for the aging laboratories that altered world history — and, some say, darkened it.
The Hanford site produced plutonium. The Oak Ridge site enriched uranium. And workers in Los Alamos used those materials to assemble the Little Boy and Fat Man bombs dropped on Japan, forcing a Japanese surrender and ending the war. Some 200,000 civilians in Hiroshima and Nagasaki perished.
The Advisory Council on Historic Preservation called the bomb's creation and use "the single most significant event of the 20th century" in advocating for the preservation of buildings once scheduled for demolition.
The president of the Japanese American Association of New York is not as nostalgic. Any commemoration of the sites, said Gary Moriwaki, should educate visitors "on the devastating effects of the bombs dropped on" Japan.
"One should reflect on the words of J. Robert Oppenheimer," Moriwaki said. " 'I am become death, the destroyer of worlds.' "
Oppenheimer, a physicist, guided the project at Los Alamos and has been called the father of the atomic bomb.
Today, thousands of scientists continue to work in those labs on unrelated research, giving life to pioneering technologies now used for the Mars rover, chemotherapy, whole-body X-ray scanning at airports, high-speed computers and biotechnology — a legacy of the brilliant scientists who worked at the sites during World War II, Energy Department officials said.
"You can't deny the impact nuclear weapons have had," said Micah Zenko, a fellow at the Council on Foreign Relations who specializes in nuclear policy. Zenko said preserving the Manhattan Project sites makes sense. "It's a part of American history that most people forget."
America's race with Nazi Germany to develop the first atomic bomb received its code name, the Manhattan Project, in late 1941. Its official formation in the Manhattan Engineering District followed in August 1942.
That same year, the Hanford reservation in eastern Washington along the Columbia River was selected to produce plutonium. The Oak Ridge and Los Alamos labs were established in 1943. In all, 125,000 people worked on the project at those sites and Manhattan, and only 1,000 knew the exact purpose of the work. About 32,000 people currently work at the sites.
Each site has some nuclear-waste contamination and is undergoing cleanups involving up to 30,000 workers under multibillion-dollar contracts, said David G. Huizenga, senior adviser for environmental management at the Energy Department.
A proposal for a park designation by Sen. Jeff Bingaman, D-N.M., is slowly working its way through a committee. Companion House legislation proposed by Rep. Doc Hastings, R-Wash., is awaiting a full vote.
As a national park, Oak Ridge could easily top the 1,500 visitors who swing by each year for a tour conducted by the Energy Department five days a week from June to September, said Katy Brown, president of the city's convention and visitor's bureau.
She has taken the tour bus that boards at the nearby American Museum of Science and Energy past the tall laboratory fence. The graphite reactor, she said, is an awesome sight.
"It's really cool. It's very nostalgic," she said. The tour led into an old control room where a logbook encased in glass showed when the reactor first went critical, about 5 a.m. on Nov. 4, 1943, allowing scientists to move ahead with plans to extract plutonium from uranium.
Seventy-five thousand people worked on the Manhattan Project at Oak Ridge, Brown recalled the tour guide saying. Sixty cents of every dollar spent on the project went there.
Brown said she wants more Americans to take the tour. She wants to grab some of the tourists who speed by on their way to Dollywood or visit the Smoky Mountains.
"We're an ideal location to tell this story because people are driving past us all the time," she said.
At the Los Alamos National Laboratory, there are no tours currently, a spokeswoman said. But Cynthia Kelly, president of the Atomic Heritage Foundation, which worked to preserve the three sites, hopes a national park designation will open the Los Alamos site to tours that would include garagelike buildings where the bombs were actually assembled and Oppenheimer's old house, a small cottage where a woman, now 93, has lived since 1951.
The woman signed over the house to the Los Alamos Historical Society with the understanding that she could live there as long as she chose, Kelly said.
"When I first met her, she said you must come see the house," Kelly recalled. "She said, 'I haven't changed a thing.' "