Mountains of trash, recurring fires, despoiled natural springs, vandalized historic sites and disappearing wildlife are part of the devastating toll that the government's running battle with smugglers and migrants is taking on national parks and wildlife refuges along the U.S. border with Mexico.
In southern Arizona, the damage extends to Indian and private land, jeopardizing a broad expanse of the Sonoran Desert, which boasts a greater diversity of plant and animal life than any other of the four North American deserts.
At Cabeza Prieta National Wildlife Refuge, 2 1/2 million pounds of garbage are scattered through broad valleys and desert arroyos every year, according to Roger DiRosa, the refuge manager. Officials with the U.S. Border Patrol said the refuge's seven mountain ranges -- home to bighorn sheep and a prized destination for wilderness hikers -- now serve as posts for lookouts who use night-vision equipment to track the movements of the Border Patrol. Mountain peaks conceal clandestine radio repeating stations that are part of smugglers' surveillance operations.
Illegal "ghost roads" carved by smugglers and pursuing federal agents crisscross Cabeza Prieta and nearby Organ Pipe Cactus National Monument. Sections of Organ Pipe are deemed so dangerous that the National Park Service has closed them to the public.
Officials at the U.S. Department of the Interior said they are considering giving the Border Patrol control of the hard-hit areas of the refuge and park nearest the border.
"We've talked about what kind of swath they would need, how much we would let them control, recognizing that you would be sacrificing a small area for the greater good," said Larry Parkinson, Interior's deputy assistant secretary for law enforcement and security.
"You've got to give up a little to save a lot," Parkinson said. "If we don't help Border Patrol improve their control over the border, we won't have anything left to save."
On a recent tour of the damage, DiRosa, who manages Cabeza Prieta for the U.S. Fish and Wildlife Service, steered his truck toward the Growler Mountains, making slow headway through 2 feet of what used to be fertile desert topsoil. A constant stream of vehicles had pulverized the sand into a fine powder that DiRosa and other federal land managers here call "moon dust."
There is only one official road in Cabeza Prieta's 860,000 acres, and this wasn't it. The nameless routes, stretching north from the Mexican border, are the result of an estimated 1,000 illegal foot crossings a day and countless vehicles transporting undocumented migrants, drug runners and the Border Patrol.
The constant human pressure is threatening to eliminate the area's wildlife. The refuge's population of the endangered Sonoran pronghorn, a deer-like creature, had fallen to 21 -- down from 179 in 1992 -- and the species was headed for extinction before a captive-breeding program was established in 2004.
Cabeza Prieta alone has 400 plant species and 300 types of wildlife, including ringtail cat, kit fox, bighorn sheep, javelina, badger, bobcat, mule deer, desert tortoise, 24 species of snake, 11 species of bat and 212 species of birds.
It's only a matter to time, officials say, before these animals' home is rendered uninhabitable.
Federal officials describe the effects of massive trespass as "staggering" and warn of dire repercussions to rare wildlife and sensitive desert, where nature may take decades to erase a single boot print.
"We're getting hammered," DiRosa said, calling Cabeza Prieta the most embattled wildlife refuge in the United States. At Organ Pipe, Supt. Kathy Billings said she can't argue with a conservation group's 2004 assessment that the national monument is one of the nation's most imperiled.
East of Organ Pipe, residents of the Tohono O'odham Indian Reservation recently removed more than 7,000 abandoned vehicles.
Wendy Glenn, whose family runs a cattle ranch near Douglas, described the harm done to livestock and wildlife.
"There are at least two semi [tractor truck] loads of trash in the canyon behind us, and there are probably seven canyons like that," she said. "Our cattle eat the trash. Little animals stick their heads in bean cans and walk around with the cans on their muzzle until they die. Our neighbor had a cow in a corral -- it was having a problem calving. They came back in the morning to check on it and two illegals had killed the calf and were cooking it.
"There's constant harassment of wildlife," Glenn said. "Deer don't feed during the night because there's too many people running around. They need to go into the thickets to shade up during the day, but they go in now and there's people there, along with trash and fecal matter."
Arizona's border with Mexico, more than 350 miles long, includes six national parks, three wildlife refuges, three national monuments, two national conservation areas and a national forest. Government scientists have documented the most serious damage at Cabeza Prieta and Organ Pipe.
At Organ Pipe, on Cabeza Prieta's eastern border, the National Park Service estimates that visitors hiking the park's trails may encounter 200 pounds of trash per mile each year. Wildlife biologists say trash and human waste spread disease among animals.
Soil compaction across hundreds of miles of roads and trails has killed cacti's shallow root systems, causing towering saguaro and organ pipe cacti to topple, taking with them animal food sources and bird nests. Especially vulnerable is the fist-size cactus ferruginous pygmy owl, a rarely seen endangered bird that nests in saguaro cavities.
The refuge is home to one of the nation's few birthing sites for the lesser long-nosed bat, an endangered species. Migrants hiding out in the bat's caves cause the animals to abandon their nests. Bats are vital to desert plant communities as pollinators and distributors of seeds.
At Organ Pipe, Native American relics and pioneer ranch buildings have been damaged or destroyed, Supt. Billings said. The corral from Dos Lomitas Ranch, a 19th century site listed on the National Register of Historic Places, is being taken apart board by board and the wood used for campfires.
Thirsty border-crossers are draining many scarce natural water sources and have damaged or destroyed water tanks placed by biologists for bighorn sheep and pronghorn. Dripping Springs, a centuries-old desert oasis for pioneers and prospectors, now regularly tests positive for high levels of E. coli bacteria.
Last year, 3,500 acres burned in Cabeza Prieta, said Mike Coffeen, a Fish and Wildlife biologist at the refuge. The previous annual high was 50 acres. According to refuge staff, the increase is due to "come-get-me fires" set by undocumented migrants who become lost in the desert.
DiRosa said he spends 80% of his time not dealing with the wildlife protection duties for which the refuge was established in 1939, but mired in paperwork on border security. He likens his management decisions to triage, sacrificing the welfare of some plants and animals to save the refuge as a whole.
"It's like every day you get up and get slapped 10 times," he said. "One day, you only get slapped seven times and think, 'Hey, that feels good.' But your face is still raw. We're just trying to reduce the destruction."
Preventing damage is complicated by the Border Patrol's virtual immunity from laws designed to protect the border environment. The Real ID Act, enacted last year, gives the U.S. Department of Homeland Security authority to exempt its operations from environmental laws.
Border Patrol agents pursue illegal immigrants in high-speed chases across fragile desert lands. Driving in the area normally would be prohibited by the Wilderness Act.
The agency has established camps in wilderness areas, obliterating plants to make way for helicopter pads, trailers, fencing, generators and high-intensity lights. Since much desert wildlife is nocturnal, the noise and lights have driven animals out of their natural habitat.
Environmental groups and others contend that the Border Patrol's own policy, adopted in the mid-1990s, to reduce border crossings near urban areas has shifted the illegal traffic from Southern California and Texas to environmentally sensitive federal lands in Arizona.
"Arizona is getting hammered because of enforcement efforts elsewhere," said Daniel Patterson, a desert ecologist with the Tucson-based Center for Biological Diversity.
Last year, according to the Border Patrol, a record 267 people died crossing the Arizona desert, where 100-degree temperatures for 100 consecutive days are not uncommon. Already this year, the Border Patrol reported, 30 people have died in a region more inhospitable than usual after four months without rain.
"What would this be like if the Border Patrol was not here?" DiRosa mused, walking around a bullet-ridden white station wagon stuck in the sand. "I'd shut the door, because the refuge would be so damaged and compromised. But the Border Patrol is a Catch-22: They protect the refuge but damage the wilderness."
The Border Patrol says it now requires environmental sensitivity training and mandates that agents who drive through wilderness areas report incidents to refuge or park managers.
"We've come a long ways," said Ron Colburn, the Border Patrol's chief patrol agent for the agency's Yuma sector. "It has been an evolution in the cultures of the U.S. Fish and Wildlife Service biologists and Border Patrol personnel. We were both operating in the same area, but had recognizably different missions. We didn't see our missions joining."
Now they do, Colburn said, citing a pending national agreement between the Border Patrol and several federal land and wildlife management agencies that seeks to reduce conflict and spell out how to operate in sensitive habitat.
In some cases, federal land managers must weigh damage from border protection projects against the future destruction they forestall. At Organ Pipe, installation of an $18-million vehicle barrier scraped away a 30-mile swath of the park's southern border, but has successfully reduced illegal vehicle traffic by 95%.
"The reason Organ Pipe was created was to preserve the Sonoran Desert," Supt. Billings said. "If we lose Organ Pipe and it becomes a moonscape as a result of these impacts, we lose our heritage."