Havana St. and E. 56th Ave., Commerce City
303/289-0930
www.fws.gov/rockymountainarsenal

HOURS: Tues.–Wed. and Sat.–Sun. 6 a.m.–6 p.m. (tours)

COST: Free

It’s an odd combination: nerve gas, natural beauty, and tourists. But somehow it works—and the Rocky Mountain Arsenal National Wildlife Refuge has become one of Denver’s gems less than 15 miles from downtown.

It’s easy to spend the better part of a day at this prairie oasis on a guided bus tour or walking through the miles of trails that traverse woodlands, wetlands, and prairie. Every season there is a chance to see some of the 300-plus species that call this place home, and it’s become a destination for bird-watchers.

Summer is the best time to see burrowing owls and Swainson’s hawks; in spring, the migratory song birds and pelicans fly in; fall brings an opportunity to watch deer with their full antler racks and in winter the bald eagles are more visible.

Anytime of year you might spy coyotes, raptors, prairie dogs, and a variety of waterfowl and birds. Over 20 bison—which were brought from Montana in 2007—live at the refuge and can be seen easily on most tours.

As the name suggests, the Rocky Mountain Arsenal National Wildlife Refuge was not always a wildlife refuge. In the 1940s the U.S. army took possession of family farms to create a 27-square-mile chemical weapons facility, Rocky Mountain Arsenal. Mustard gas and napalm were manufactured here before the site was used to make agricultural pesticides.

While the center of the Arsenal has been described as one of the most polluted square miles on Earth, the buffer zone was attracting wildlife for decades. A 1989 New York Times headline about the Arsenal reads, “Nature Sows Life Where Man Brewed Death.” In the 1990s the wildlife was fenced in and work began to turn it into a wildlife refuge. Optimists talk of how nature has triumphed here, while skeptics point out soil contamination concerns.

The arsenal is closed sporadically for months at a time for ongoing clean-up efforts, which are expected to be completed by 2011.