Issue 4, Winter 2003-04


A Haven for Wildlife…and Trash

A sweeping view of the Cabeza Prieta NWF. Photo by Jay Krienitz.Boundless desert surrounds you in Cabeza Prieta National Wildlife Refuge. Here, seven rugged mountain ranges cast shadows over barren valleys once swept by lava. Saguaros loom in stark profile above the baked earth. Imagine the state of Rhode Island without any people and only one wagon track of a road. Cabeza Prieta NWR is that big, that wild, and also incredibly hostile to those who need an abundance of water to live. Yet, within a landscape at once magnificent and harsh, life thrives in a variety of captivating flora and fauna species. More than 90 percent of the refuge was designated as wilderness as part of the 1990 Arizona Wilderness Act, making it the largest refuge wilderness administered by the U.S. Fish and Wildlife Service in the lower 48 states.

In the Cabeza, a 56-mile, shared border with Sonora, Mexico, has been called the loneliest international boundary in the country. But this shared border is putting pressures on the refuge and other border wildernesses unlike those facing other protected public lands in the U.S. interior.

The thousands of undocumented immigrants who cross this border area from Mexico into the United States daily are taking a heavy toll on wildlife habitats and the species that live in southern Arizona, especially in our most critical wild lands, say natural resource managers.

While definitive studies on wildlife and habitat haven't been done to show the quantitative and qualitative effects of illegal border activities, much documentation regarding impacts does exist. Biologists say that general off-road traveling and hundreds of miles of illegally crated roads and trails are the most damaging.Endangered Sonoran pronghorn are seriously threatened by illegal travel in the refuge.

Biologists say animals such as deer, javelina, endangered Sonoran pronghorn, other mammals such as bobcats and ringtails, and certain species of bats and birds are most at risk where undocumented immigrants cross and/or congregate. Other threatened, endangered, and sensitive species of animals and plants are suffering as well. The lesser long-nose bats, for example, whose caves have been used by illegal immigrants for shelter, are being driven from their maternity roosts by activities of illegal immigrants and drug smugglers on the Cabeza Prieta.

Destruction of habitat and disturbance of wildlife are only part of the problem. Illegal crossers leave behind large amounts of litter, such as empty water jugs, old clothes, cans and bottles, and paper. Some border areas simply look like city dumps.

Does this look like one of America's treasured public lands? Compounding the problem if trash is the large amount of human biological waste that accumulates in staging areas or pickup points, especially near riparian zones. The resulting pollution and risks to legitimate users of these streams and river beds are of a major concern to land managers who state that some areas have such large accumulations of waster that they are bio-hazard sites and must be treated accordingly for cleanup. Even cleaning these trash heaps and waste sites is problematic because they are soon returned to pre-cleanup levels by the large number of illegal immigrants continuing to cross the border.

Estimates made on the Tohono O’Odum Indian Reservation that borders Mexico for 73 miles have indicated that approximately 8 pounds of trash is left behind by each immigrant and drug runner who crosses border lands, including the Cabeza. The scattered and accumulated trash in Arizona border wilderness areas and other public lands amounts roughly to a staggering 1 to 2 million pounds each year.

In more remote areas of border wilderness such as the Cabeza Prieta, illegal vehicular traffic causes more extensive damage to the delicate desert microbiotic soils and leads to the destruction of plants, alters drainage patterns, and disturbs wildlife. At any given time, there are 20-25 broken down or abandoned vehicles in the wilderness portion of the Cabeza that are left by smugglers. Staff efforts to remove the vehicles cannot keep up with the accumulation and their removal further damages refuge resources.

Approximately 140 miles of illegal roads have been created on the Cabeza in the last 3 years. The impacts of this network are compounded by the needs of law enforcement that must engage in the interdiction of drug and people smugglers and conduct search and rescue operations bySunset on the Sonoran Desert. both ground and air. Efforts are made to keep excess off-road travel to a minimum and maintain wilderness character, but too often there is no other alternative than cutting across wilderness lands, especially when lives are at stake, says refuge manager Roger Di Rosa. Lives are often at stake in these remote desert areas where summer temperatures can soar to 115 degrees and higher.

“The Cabeza doesn’t stand alone in efforts to protect and manage its wilderness resources against these new threats,” says Di Rosa. “The whole Arizona border has become a battle zone for law enforcement officers and resource managers.”

Di Rosa says that sensors on the Cabeza have indicated that 4,000-6,000 illegal immigrants a month cross the eastern portion of the refuge each spring. Their neighbor, the Organ Pipe Cactus National Monument, estimates that 300,000 illegal individuals cross there over the course of a year’s time. The monument has just commenced building a vehicle barrier long the border, which could only increase the number of illegals using the Cabeza border wilderness areas.

A blooming desert cholla.“Those of us trying to manage public lands on the border have now found our mission expanded to things that we rarely considered in the past,” says Di Rosa. “Now our heightened concerns and responsibilities include homeland security on a remote international border, high intensity drug and people intervention, and escalating risks to staff and visitors. These aren’t your parents’ borderland parks and refuges anymore.”

You Can Take Action!

The Cabeza Prieta is currently engaged in completing a Comprehensive Conservation Plan, which will be a refuge management plan, wilderness management plan, and Environmental Impact Statement in one package. It will guide refuge managers on future priorities and establish goals for protecting and managing species and their ecosystems within the Cabeza Prieta.

Draft action alternatives for wildlife habitat, recreation, and wilderness management are tentatively scheduled for public review by March 2004. Public hearings will be held and comments on the draft document will be accepted through June 2004.

For more information about the refuge and the planning effort, visit, or contact the refuge by phone: 520-387-6483. Stay connected with the Arizona Wilderness Coalition for more details about the Cabeza this spring.