I’m wandering along in a trance, placing one boot in front of the other, and silently considering the fissures in the dry soil along the trail. This is what I tend to do outdoors—daydream. Today, however, I’m jolted out of my haze when I catch sight of something out of the corner of my eye. I look up to find a white-tailed deer staring at me. A piece of long, green grass dangles from her mouth. She stands very still, as if she’s giving me the chance to take in the woodsy scene, but I’m too distracted by what’s behind her to notice. A sign that reads By Order of the Army, Do Not Enter hangs on a spiderweb of fencing just feet away.

I should have expected to see such signage, considering that I’m hiking on land that used to belong to the Rocky Mountain Arsenal, a chemical weapons manufacturing facility that cropped up in 1942. The Arsenal, as it became known, produced weapons and served as a munitions plant and POW camp for nearly 40 years until it closed in 1983.

But that was long ago. These days, the 27-square-mile area, just 11 miles northeast of downtown Denver, is gaining recognition for its much-anticipated future, not its past. An environmental cleanup of the Arsenal began in 1988, and four years later the area was designated a future national wildlife refuge. Still under construction, the Arsenal is currently both a wildlife refuge and a Superfund cleanup site, a designation that means it’s still on the federal government’s list of hazardous waste sites.

Unlike welcoming state parks, the Arsenal lies behind an eight-foot, chain-link fence, a boundary you must cross at the refuge’s entrance. Signs warn guests not to venture off the main road to the visitor center, so I stay the 1.5-mile course. The wide-open space, flat and beige, appears desolate. The visitor center, however, is flush with activity—and more visitors than I’d expected.

The true irony of this new recreation area doesn’t hit you until after you enter the main room of the center. Mixed in with the coyote and bald eagle displays are sepia-toned photographs of “Honest John” rocket warheads, body suits complete with gas masks, a bombproof phone, and soil contamination diagrams. I find myself skimming over the wildlife exhibits, drawn to the more disturbing ones. For more than 20 years, workers here assembled napalm bombs and manufactured mustard gas, the blistering agent lewisite, and sarin gas. From 1952 until the early ’80s, the Army leased portions of the land to private companies, which in turn produced commercial-grade pesticides onsite. Although all manufacturing operations at the Arsenal ceased in 1982, years of accidental spills and shoddy waste-disposal techniques resulted in the contamination of surrounding soils and groundwater.

After the gruesome lesson in the visitor center, I’m reluctant to hit the Arsenal’s trails, but I head out anyway. I start off on the scenic Lake Mary Trail, meandering around the small man-made pond. Towering cattails obstruct my views in some areas, then open up to reveal vistas that extend west to the snowcapped mountains and south to the blurry outline of downtown Denver. Several people are fishing from the shoreline decks, while a nearby group of retirees stands stock still, binoculars glued to their eyeballs in an attempt to see a mountain bluebird. More than 330 species of animals call the area home, including bison, coyotes, badgers, and deer.

Leaving the anglers and birdwatchers behind, I head to the three-mile Ladora Trail. I wander along in silence. Every now and then I pass a monitoring well used to examine the flow and contamination of area groundwater. The rusty, white pipes jutting up from the ground seem out of place in the short-grass prairie, but then the entire refuge seems just a bit off when you think about it. While watching a pair of ducks bob in the water, I can’t help but wonder if the water they’re sticking their sleek necks into is clean. My shoes aren’t glowing green. My lungs feel clear. But what about the wells and the gas masks and the water contamination display? How safe is this place, really?

There’s no need to worry, says Steve Berendzen, the Arsenal’s refuge manager. “All of the contaminated materials have either been moved, incinerated, or covered,” he tells me a few days after my visit. “The cleanup is still ongoing, but there is no threat to the public, no exposure.”

He’s correct in that 80 percent of the site has already been deemed “clean” by the Army and transferred to the U.S. Fish and Wildlife Service for ongoing management. But as the Army wraps up the task of building covers over the landfills and consolidation areas, there have been serious hiccups. In October 2007, air monitors caught a whiff of the blistering agent lewisite, and the refuge was closed for nearly eight months. Then, last summer, the Arsenal issued a press release titled, “Experts Safely Dispose of Laboratory Jar at Rocky Mountain Arsenal.” The jar, it turns out, had crystals forming on its lid, which meant there was “a slight risk that opening the jar could trigger an explosion.”

Such distressing reports aren’t keeping people away, though. Visitor numbers have been on the rise, according to Berendzen, who estimates nearly 30,000 people will visit the Arsenal this year (compared with 20,000 in previous years). People come to enjoy some of the most accessible open space near Denver, not to mention refuge-sponsored nature walks, photo tours, and environmental programs. And plans are under way to construct a larger visitor area and additional hiking and biking trails. In the future, Arsenal operators hope to erect an open-air tram and a paved perimeter trail. Once those projects are complete, the Arsenal will become one of the country’s largest urban national wildlife refuges.

My trail eventually intersects a dirt pathway, and I follow it aimlessly as I consider the past, present, and future of the land underfoot. As I walk, I can’t help but scan the ground. I’m not sure what I’m looking for. Corroded munitions? A suspect jar? Something else the cleanup crews overlooked? But I don’t find anything. Instead, I find nature doing what it does best, reaching skyward, covering up our mistakes, and thriving despite our best attempts to thwart it. Nature is moving on, as if it’s already forgotten the past—or, at the very least, forgiven it.

Stephanie Powell is a Denver-based freelance writer. E-mail her at letters@5280.com.