TUCSON, Ariz. -- The Cabeza Prieta National Wildlife Refuge, a sweeping desert preserve abutting the border with Mexico, is among the nation's most endangered, a conservation group says.
The refuge in southwestern Arizona is home to the endangered Sonoran pronghorn. But drug and illegal immigrant traffic and Border Patrol operations are taking a heavy toll on the refuge, the nation's largest outside of Alaska, says the Defenders of Wildlife.
Human presence has damaged the fragile wilderness, threatening wildlife and habitat, according to a report being released last month by the conservation organization. The report calls for construction of a costly vehicle barrier on the southern edge of the refuge along the Mexican border.
"We're trying to highlight the fact how special this place is, but it's also at a crossroads," said Noah Matson, a Defenders of Wildlife director in Washington who wrote "Refuges at Risk: America's Ten Most Endangered National Wildlife Refuges 2004."
The nation has 540 wildlife refuges encompassing nearly 100 million acres. The 10 cited Friday included five in the West. The other four were Nevada's Desert National Wildlife Refuge Complex; Don Edwards San Francisco Bay National Wildlife Refuge in California; Klamath Basin National Wildlife Refuges in Oregon and California; and the Arctic National Wildlife Refuge in Alaska.
The report says the 10 face some common threats, ranging from human presence to nearby development, pollution or invasive species. Escalating industrial and corporate development close to and even inside refuges is the most pervasive threat today, the report said; about three dozen refuges have more than 1,800 active oil and gas wells.
A systemwide fund shortage for refuge operations exacerbates the problems, the conservation group said.
Matson said the Cabeza Prieta is a prime example.
"The reason it's on the map is increased border traffic and Border Patrol operations," he said. "The Cabeza has become Ground Zero."
In recent years, Arizona has become the nation's busiest entry point for illegal immigrants from Mexico, and clampdowns in populated areas funneled many immigrants and their smugglers into the state's western deserts, including the Cabeza Prieta.
High-speed off-road chases, abandoned vehicles, numerous deaths and damage to fragile desert landscapes have resulted.
"In an attempt to curb illegal border crossings and prevent further deaths, border officials have established permanent camps in the refuge, incongruous with this once-pristine and remote place, but reflecting the intensity of the problem," the report says.
The increased traffic threatens the already slim chance the endangered Sonoran pronghorn has of survival, the report says. Refuge officials now estimate the population at 30 to 40 animals at most.
Refuge manager Roger Di Rosa said the report is right about the threat to Cabeza Prieta.
"The border issue is convoluted and very complex," he said. "The solution to the border problems is not on the border; it's in Washington, D.C., and Mexico City. So we're just putting a Band-Aid on the wound to stanch the blood. It's a difficult situation."
The U.S. Fish and Wildlife Service, which oversees the refuge, and the Border Patrol are trying to accomplish their missions without degrading the border, Di Rosa said.