Even those who know the area best won't step far off the narrow, muddy road that runs through the center of the desolate toxic dump at Utah's Deseret Chemical Depot.

It's been more than 30 years since the U.S. Army used this vast scrubland, known as the East Demilitarization Area, to dispose of a deadly arsenal of chemical and conventional munitions -- but the military still hasn't figured out how to clean up its mess.

The Defense Department does acknowledge the disaster, just as it has belatedly admitted having tested a gamut of chemical and biological weapons on military members in Utah's vast west desert during the Cold War. But the U.S. government insists that the tests have contributed to long-term illnesses in only a handful of exposed service members. And that has led the Department of Veterans Affairs to deny almost all claims for care and compensation made by those who believe they got sick as a result of the tests.

Although the Cold War was fought mainly by proxy and politicians, it was not without its casualties: Many died while waiting on the military to so much as acknowledge its secret programs.

Now, Dwight Bunn fears he might also slip away before the government takes responsibility for its actions.

The former soldier is sick. And he wants to know why.

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'Don't worry, this stuff won't hurt you.'

Bunn was 21 years old when he arrived at Dugway Proving Ground, just over the snow-dusted hills from the Deseret demilitarization dump, in Tooele County. The official mission of his unit, the 45th Chemical Company, was to create smoke screens for infantry assaults. But in the early 1960s, at the height of the Cold War, the Army had other uses for the group.

Among the company's secretive duties: Helping to dispose of the carcasses of animals used in chemical weapons tests.

Starting in the 1940s and continuing through the 1970s, the Army tested and disposed of thousands of tons of chemical and biological agents in sparsely populated Utah, including munitions loaded with sarin, VX, mustard, tabun and various hallucinogens.

Bunn, whose tour of duty in Utah began as the U.S. was beginning to build up its forces in Vietnam, also believes members of his unit were exposed to Agent Orange. "They told us, 'Don't worry, this stuff won't hurt you. It's a defoliant and so it will kill the trees, but you'll be fine," he said.

Bunn said military officials have told him they can find no record of Utah tests involving the toxic herbicide, which has been linked to dozens of medical conditions.

But for the Washington state man, the government's denials are less than convincing. After all, the military spent years disavowing the tests altogether. The denials ended in the late 1990s, but the government has offered medical care and compensation only to those who can establish, by a preponderance of evidence, their illnesses were the result of exposure.

As of 2008, just 39 of 614 benefit claims filed by veterans in relation to tests nationwide had been approved.

Bunn, who suffers from restrictive lung disease, has asked the VA for care and compensation for his condition, in which tissue surrounding the lungs hardens and makes it difficult to exhale.

But the 65-year-old veteran's claim has been denied. And he's infuriated by a government that kept the program secret for decades, and now expects him and others to be able to offer proof that the tests made them sick.

"I've been exposed to a hell of a lot of stuff," he said. "Can I say definitively what did this to me? No I can't. But I've never lied about it. The military -- it conducted tests on humans and didn't acknowledge it. That's not right."

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'Blow it up and burn it.'

Long rows of wooden pallets, stacked with bomb casings and ragged pieces of shrapnel, memorialize the Army's last attempt to clean up the Deseret demilitarization dump. The inefficient bomb-by-bomb effort was abandoned in the 1980s when military leaders realized it was too dangerous to continue.

"They just walked away," said Troy Johnson, Deseret's environmental program manager.

It's hard to understand why they even started. Just to the south of Deseret's colossal, modern weapons incinerator, the charred shells of nearly 60,000 mortars form an artificial bluff hundreds of feet across. Some of the bombs are believed to be filled with the hardened remnants of mustard agent.

Not far away, ditches the size of swimming pools are filled with paint cans, fire extinguishers, oil drums, tear gas canisters and cluster bombs. Unexploded ordnance litters the ground.

When a lightning fire blazed through Deseret in 1999, explosions sent white smoke into the air as long-discarded phosphorus grenades were ignited. In some areas, the soil has a green hue; military environmental experts believe that's where napalm was dumped.

The toxic disaster area covers thousands of acres.

"It was perfectly acceptable, back then, to just take this stuff out here, blow it up and burn it," Johnson said. "Today, when we discard of these weapons, we have to be 99.999 -- and then some more nines -- percent clean. Back then, out here, they simply lit a match."

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'You're supposed to be obedient'

David Davidson can't say definitively that he was sickened by his exposure to mass destruction munitions at Dugway -- but he can't say he wasn't either.

"The question is: Who knows?" said Davidson, who suffers from several types of cancer, kidney failure and heart disease and undergoes 12 hours of dialysis each week. "All I know is that I have a list of things wrong with me, but I've never been given a list of the things I was exposed to."

The VA has denied the 73-year-old veteran's requests for care.

The Army asserts it tested biological and chemical agents on "volunteer human subjects." But Davidson -- who arrived at Dugway in 1961 -- takes issue with the notion that the tests were in any way voluntary.

"I was a PFC -- a private first class," Davidson said. "You know what that means? That means I did anything they told me to do."

Once, Davidson recalled, he and other soldiers were packed into the back of an M35 cargo truck and driven into the desert, where a grid had been set up with stakes and string. "They stood us all out there, each at a different distance from where they were going to set off an explosion and told us to stick it out as the gas went off. Then we were supposed to come back and tell them how it affected us."

Davidson doesn't know what the gas was, but it created "a big fog" and sent him to his knees, gasping for breath.

"It's interesting that they would do such a thing," he said. "But when you're in the military, you're supposed to be obedient, and I did what I was told."

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'They said this never happened.'

For decades, military leaders remained silent about "Project 112," a slew of tests overseen by the Army's Deseret Test Center in Salt Lake City. Beginning in the 1960s, the program tested chemical and biological agents, including VX, sarin and e. Coli, on unknowing military personnel.

When the tests were finally acknowledged, the Defense Department agreed to help the VA track down those who were exposed. But in a report issued in 2008, the General Accountability Office scolded the military for its lackluster effort.

According to the report, the military arbitrarily ended its attempts to find victims in 2003 -- even as some veteran advocates were finding hundreds of others whose illnesses might have been caused or aggravated by their exposure.

The GAO report didn't surprise Douglas Rosinski, a Washington, D.C., attorney who represented a group of veterans that helped force an end to years of Pentagon silence about the tests.

"For 40 years, they said this never happened," Rosinski said. "I would be surprised if the government was still being anything other than absolutely reluctant."

Michael Kilpatrick, director of strategic communications for the Military Health System, said a renewed effort to locate service members exposed to chemical and biological testing will likely conclude in 2011.

More than 60 years after the testing began, Kilpatrick said, the government is still investigating "what exposures each individual may have had and to evaluate each individual's current health."

In the meantime, he said, "these individuals are eligible for an evaluation by the VA."

And, for most, that's all they'll get.

Meanwhile, veterans who were exposed to the tests are fading into history. Bunn, the former soldier who was assigned to pick up animal carcasses, knows of just one other man from his unit who is still alive. "And the last time I spoke with him, he was having trouble remembering much about what happened out there."

Ultimately, Bunn said, the human evidence of the tests will be gone. "All that will be left is the desert we used to stomp around in," he said.