Plastic water bottles, clothes and plastic food bags pile up in areas under low-lying mesquite trees. An abandoned pickup truck sits 16 miles north of the border in an area so remote that officials can't tow it out.
Being located in one of the busiest corridors for illegal immigration and drug smuggling on the U.S.-Mexico border has put the 118,000-acre Buenos Aires National Wildlife Refuge at center stage of the daily duel between smugglers trying to get their loads into the country and Border Patrol agents trying to catch them.
Nearly a decade of this activity has left scars on the refuge and has landed it on an undesirable Top 10 list — the most imperiled national wildlife refuges in the country, according to a report by Public Employees for Environmental Responsibility. The list, which doesn't rank the 10 sites, also includes the Cabeza Prieta National Wildlife Refuge, in Southwestern Arizona.
It's the second time each refuge has been included in a dubious Top 10 list of this type. Defenders of Wildlife named Buenos Aires among the 10 refuges most at risk in 2005, and Cabeza Prieta in 2004.
This is the first list published by Public Employees for Environmental Responsibility. In total, the National Wildlife Refuge System encompasses more than 540 refuges in all 50 states.
The report emphasized damage done at both refuges by border fencing and illegal roads created by Border Patrol agents who use sport utility vehicles, Humvees and all-terrain vehicles.
The refuges' imperiled status is a direct result of the federal government's failed strategies that have "militarized" the border and pushed smuggling into more remote areas, said Daniel Patterson, an ecologist and Southwest director of Public Employees for Environmental Responsibility.
"There are certainly environmental impacts from smuggling, and there is no defense to breaking our nation's law to enter the country," Patterson said. "But agents chasing immigrants in huge trucks — that's a disproportionate impact."
The Department of Homeland Security needs to impart a better sense of environmental stewardship on its Border Patrol agents, he said. There is a "real lack of responsibility of trying to protect the environment of the country they are sworn to protect" among many, but not all, of the agents, Patterson said.
Refuge managers don't deny that their lands are imperiled —the report highlights what they've been dealing with since the late 1990s, when Arizona became prime real estate for smugglers.
"No one likes to be on a list like this," said Curt McCasland, assistant manager of the Cabeza Prieta National Wildlife Refuge.
"But I think it's fair. … We are stuck in the middle of a lot of this border stuff. … The amount of impacts that have occurred in terms of the vehicles going across and the people going across — it's just devastating."
But McCasland and Sally Gall, acting Buenos Aires Refuge manager, have different opinions on how much blame should be placed on the Border Patrol.
Though Gall said she understands the need to go off road at times to pursue smugglers, she said that not all agents show the same respect for the refuge's regulations.
"Some are very aware and respect that and try to stay on roads, and then others, umm, don't," Gall said. "The fact that there are so many vehicles out here, around the clock, every day of the year, probably has more of an impact than those walking on foot through this refuge."
McCasland said it's unfair to blame the Border Patrol, because agents wouldn't be on the refuges if people weren't crossing illegally. Without their presence, the impact on the refuge would be much worse, he said.
"If Border Patrol doesn't get out there, that's when we really get hit," he said. "If Border Patrol is effective, we win. It's important to never lose sight of that. … If they make it so difficult for folks to come through here, they'll go somewhere else, and we won't be dealing with the impacts that are going on."
Agents sometimes have to go off road to catch drug smugglers, but that doesn't occur as often as the report insinuates, said Brandon Judd, vice president of Local 2544, the local chapter of the Border Patrol agents' union, called the National Border Patrol Council.
Agency policy requires that agents stay on established roads or face discipline, he said.
He scoffed at the claim that agents cause more harm than illegal immigrants do.
"You go to these lay-up spots and you'll see more trash than you'll see at a dump," Judd said. "That's ridiculous to say that we're doing more damage to the land than illegal aliens."
The Buenos Aires National Wildlife Refuge, about 45 miles southwest of Tucson on land that primarily is east of Arizona 286 in the Altar Valley, was established in 1985 to preserve and restore the largest ungrazed grassland in Arizona and wild-life, including the endangered masked bobwhite quail.
By 2000, about 3,000 illegal immigrants a day were coming north through the Altar Valley, Gall said. It stayed nearly that busy until 2006 and has tapered off slightly since, she said.
In October 2006, the refuge closed 3,500 acres along a five-mile stretch of the U.S.-Mexico border to protect visitors. The land remains closed.
The reckless off-road-vehicle use on the refuge fragments habitat, harms wildlife and increases the risk of unnatural fires, the report says. Though hunters contribute to the damage, most of it is caused by Border Patrol agents, Gall said.
The turnaround points they create on the sides of the roads also harm the habitat, she said.
Refuge officials have placed temporary vehicle barriers on the north side of the road near the entrance to keep agents from parking and turning around there, she said.
She and her 15-person staff spend at least half of their time, and some weeks nearly all of their time, dealing with border-related issues, she estimates.
The five law-enforcement officers on the refuge spend at least 95 percent of their time on border-related issues, said Kyle Todd, the supervisory law-enforcement officer on the refuge.
"We cannot function as a normal wildlife refuge out here," Gall said. "We can't seem to stay focused on any one project related to the refuge, because the border-related issues kind of take us away or fill up some of our schedule."
The 860,000-acre Cabeza Prieta National Wildlife Refuge stretches along 56 miles of U.S.-Mexico border and across the Pima-Yuma County line in South-western Arizona, about 115 miles west of Tucson.
Marked by seven rugged mountain ranges, valleys and saguaros, the refuge is key habitat for the endangered Sonoran pronghorn and lesser long-nosed bat. It was recognized as one of the premier wilderness areas in the country in the mid-1990s, McCasland and Patterson said.
But as illegal immigration and drug smuggling began to be funneled into Arizona in the mid-1990s after border security was stepped up around El Paso and San Diego, the refuge was overrun by vehicles and people coming across in droves.
The vehicle traffic has dropped dramatically from vehicle barriers along the border, but the foot traffic continues, and with it the trash and the creation of trails, McCasland said.
He estimated that the 11- member staff at the refuge, which includes three law-enforcement officers, spends 75 percent to 80 percent of its time dealing with border-related issues.
The report says that despite 90 percent of the refuge being designated by Congress as wilderness — which means no vehicle traffic is allowed except on designated roads — the refuge is still deeply cut up by off-road ruts created and used by smugglers and the border agents who chase them.
"The desert ecosystem is fragile, and tracks made by vehicles or people can remain for hundreds of years," the report says.
The roads have hindered the refuge staff's efforts to maintain and increase the Sonoran pronghorn population.
Tire tracks that run perpendicular to the hills in many of the valleys soak up summer rain that used to flow into valleys and create vegetation that young fawns would eat. Without that source of food, fewer fawns survive, he said.
Like the pronghorns, Patterson said, the habitat will be slow to recover. "The Sonoran Desert is very easily scarred and very slow to heal," Patterson said.
"So the damage being done is going to last a long time."