Rocky Mountain Arsenal National Wildlife Refuge, Denver, Colorado

Location: 30 minutes from downtown Denver
Size: 15,988 acres
What to see: bald eagles, burrowing owls, great blue herons, reintroduced bison (below), black-footed ferrets

The Rocky Mountain Arsenal National Wildlife Refuge is a former federal chemical-weapons facility on the outskirts of Denver that was shuttered in 1985 and rechristened a national wildlife refuge in 1992. (The 1986 discovery of bald eagles on the then-no-man's-land site kicked off conservation efforts.) Today the largely cleaned-up Rocky Mountain Arsenal is home to some 330 species of wildlife and attracts more than 300,000 human visitors each year.

"We're so close to Denver that it's natural to do environmental education here," says Cindy Sounders, the refuge's visitor services manager. But reaching the type of residents who haven't already purchased guidebooks and spotting scopes at REI can be a challenge. "It's an economic struggle," Sounders says. "We've got a high-poverty community adjacent to the refuge. Parents may work two jobs."

Bayou Sauvage National Wildlife Refuge, New Orleans, Louisiana

Location: 20 minutes from New Orleans's French Quarter
Size: 24,293 acres, the largest urban wildlife refuge in the United States
What to see: American alligators, crabs, shrimp, white-tailed deer, 340 bird species

Much of the area that became Bayou Sauvage National Wildlife Refuge in 1990 was slated for development before the oil bust of the mid-1980s. (Today, two "ghost interchanges" along Interstate 10 end abruptly at the refuge.) Bayou Sauvage is largely surrounded by levees built to protect the once-expanding city from storm surges or flooding. Restoring native neotropical hardwoods is a priority for the refuge as well as an opportunity for locals to "get their hands dirty," says refuge manager David Stoughton (at left in photo, with Pon Dixon, deputy project leader). "We give people a reason to come back." Stoughton's kid-pleasing trick: "Dip a net in the water and pull out a lot of animals, then talk about them and about water quality."

Bayou Sauvage has teamed up with a youth-education program at the University of New Orleans, in which elementary school kids raise seedlings that then get planted by high school students. "When they see their one-year-old trees planted next to 200-year-old ones, they realize that their trees will be here two or three generations from now," Stoughton says. While the high schoolers can be aloof at first, Stoughton says, "In the end they totally get it. What they write in their journal entries after the trip can bring tears to your eyes."

John Heinz National Wildlife Refuge at Tinicum, Philadelphia, Pennsylvania

Location: 30 minutes from downtown Philadelphia (or less than an hour by public transit)
Size: 993 acres
What to see: bullfrogs, black ducks, 300 bird species (most migratory, but 80 species nest here)

Lamar Gore (above) is a natural fit at the John Heinz refuge. He grew up in Trenton, New Jersey, 40 miles up the Delaware River, mentored by a fisherman uncle. Combine a master's degree in wildlife biology with a passion for introducing Philadelphians to box turtles and migrating shorebirds, and you have your consummate urban wildlife refuge manager.

"We go into the schools, so kids have a face to go with the idea of a wildlife refuge," Gore says. His refuge is within 10 miles of 1.7 million people, and it's easily reachable by public transit. But Gore must tackle other obstacles that keep city-bred visitors away, one of the biggest being fear. "They'll say, 'There's no light down there!'" But once he's got schoolkids on-site, they're all his. "They want to play in the dirt. They want to touch the flowers, touch the butterflies, touch the crayfish. You want them to engage and lose the fear. We teach them to take time to listen and watch. It's amazing watching them go through the process from their first visit to their third."

Tualatin River National Wildlife Refuge, Portland, Oregon

Location: 30 minutes southwest of downtown Portland (or less than an hour by bus)
Size: 2,217 acres
What to see: western pond turtles, northern red-legged frogs, western brook lampreys, Nelson's checker-mallow (a threatened perennial herb)

"We don't want to be unknown to the public," says Kim Strassburg, Tualatin River National Wildlife Refuge visitor services manager, explaining why her team does outreach through Spanish-language Univision and supports a group in one of Portland's most diverse and green-space-deprived neighborhoods that is building a park on a former landfill. "People connect in their own places. We want to be an asset to the community," she says.

"When people we've made contact with in the community come out to the refuge," Strassburg says, "they see a familiar face." A highlight for her: taking kids to watch sandhill cranes at dusk. "They're silent, in awe, curious. They ask when they can come back." Hushed reverence falls aside when they see the bald eagle nest, adjacent to a highway. "That's when the kids get really excited," she says. "We want them to know that nature isn't that place on TV. It's in their backyard."

San Diego Bay National Wildlife Refuge, Chula Vista, California

Location: 15 minutes from downtown San Diego
Size: 2,620 acres (land and water)
What to see: endangered light-footed clapper rails, elegant terns (in photo), Belding's savannah sparrows, western snowy plovers, eelgrass beds, and the largest contiguous mudflat in Southern California

Brian Collins grew up in Southern California's suburbs in the 1960s. He was surrounded by nature and "had plenty of outdoor experiences." But San Diego County's population has nearly tripled since 1960, to 3.2 million.

As the manager of two coastal national wildlife refuges in San Diego and Orange Counties, Collins knows that "some of the kids coming up don't have the opportunity I had." So the San Diego Bay National Wildlife Refuge complex has partnered with outside groups to bring more than 1,200 high school students to the refuge to learn conservation science and enjoy the outdoors. "The city has too much chaos," high school student Joshua Rodriguez says in a film for the USFWS's SoCal Urban Wildlife Refuge Project. "But when you're out here, it's just wildlife. You feel immersed in a different world."

The outreach programs are a "great way to connect," says Andy Yuen, project leader for the San Diego Bay refuge. "It can be as simple as 'I got to kayak in San Diego Bay today.'" As Yuen puts it, "There's nothing better than knowing that when I leave, we will have left behind natural habitats and areas for wildlife that are better than when we started."