San Rafael Valley Closure: Impacts of 2025 Arizona Border Wall

The San Rafael Valley in Southern Arizona is a rare and irreplaceable wildlife corridor within the Sky Islands — one of the planet’s most biologically diverse mountain ranges¹. Stretching across the U.S.–Mexico border, this valley allows the free movement of endangered species like jaguars, ocelots, pronghorn, black bears, and mountain lions. It is also the birthplace of the Santa Cruz River and a tributary to the San Pedro River, supporting both terrestrial and aquatic ecosystems².

In April 2025, the Trump administration announced plans to construct 24.7 miles of border wall through the San Rafael Valley, awarding a $300 million contract to a private builder³. Using an environmental waiver signed by Secretary Kristi Noem, the project sidesteps protections designed to safeguard wildlife and waterways. Once complete, this wall will seal one of Arizona’s last open migration corridors, a move conservationists warn will cost countless animal lives and push some species toward local extinction¹.

Who Monitors the Corridor — and Why It Matters

Several organizations monitor wildlife in the San Rafael Valley, documenting the damage caused by the border wall and building the case for conservation:

• Sierra Club Borderlands Program: Advocates for wildlife passages and storm gates; partners with the Southern Border Community Coalition to document ecological harm².
• Wildlands Network & Cuenca Los Ojos: Operate a bi-national monitoring project near San Bernardino National Wildlife Refuge, capturing jaguar and ocelot movements with camera traps⁴.
• Center for Biological Diversity: Reports that full border walls block 86% of wildlife from crossing, and halt movement for large mammals entirely¹.
• Arizona Game and Fish Department (AGFD): Uses GPS collars and habitat modeling in the Arizona Missing Linkages project to map essential corridors⁵.
• U.S. Fish and Wildlife Service (FWS): Funds land purchases like the Wildlife Corridors LLC at Three Canyons Ranch to keep migration routes open⁶.

Ecological Costs — Habitat Loss Means Lives Lost

The San Rafael Valley is one of the last places where wildlife can cross the border. Building a 30-foot steel wall here will have immediate and cascading consequences.

Habitat Fragmentation

The wall will sever the connection between U.S. and Mexican ecosystems, trapping wildlife in shrinking habitat islands. In times of drought — now more frequent with climate change — animals unable to move will die from thirst, starvation, or conflict with humans².

Blocked Migration Routes

Species like pronghorn, elk, and mule deer depend on seasonal migration to survive. Walls force these animals onto highways, where wildlife–vehicle collisions often prove fatal⁵. Research shows 86% fewer successful crossings once a wall is built¹.

Loss of Ecosystem Services

By blocking movement, we lose the services wildlife provide:

• Predators like jaguars control herbivore populations, preventing overgrazing⁶.
• Bats and birds pollinate plants and disperse seeds, keeping the Sky Islands healthy⁴.

Genetic Costs — The Road to Extinction

Genetic diversity is a species’ insurance policy. The wall erases that safety net:

• Reduced genetic diversity in isolated jaguar, ocelot, and pronghorn populations makes them less resilient to disease and environmental change¹.
• Local extinction risk skyrockets for Arizona’s few remaining jaguars, already cut off from mates in Mexico⁶.

Economic Costs to People and Communities

Tourism Loss

Wildlife watching in Arizona generates billions annually. Losing jaguars, pronghorn, and migratory birds to wall-induced decline will shrink this revenue².

More Road Collisions

When animals detour around walls, they encounter more roads. Arizona already loses millions yearly to wildlife–vehicle collisions⁷.

Costly Mitigation

Restoring broken corridors requires expensive wildlife crossings and easements. The Three Canyons Ranch easement cost $2.4 million — and that’s just one small segment⁶.

Other Environmental Harms

• Light Pollution: Stadium-bright border lights disorient bats and migratory birds, disrupting breeding cycles⁴.
• Hydrological Damage: Wall foundations can alter water flow in the Santa Cruz and San Pedro Rivers, increasing flood and erosion risks².

Call to Action

This wall is more than steel and concrete — it’s a barrier to life. The San Rafael Valley is a living bridge between two nations’ ecosystems, and its closure will mean the silent loss of countless animal lives. You can help:

• Support corridor monitoring by Sky Island Alliance, Wildlands Network, and other groups on the ground.
• Contact lawmakers to demand wildlife-friendly border policies and end environmental waivers.
• Share this story to keep the San Rafael Valley on the world’s radar.

Sources

1. Center for Biological Diversity
2. Sierra Club Borderlands Program
3. Department of Homeland Security
4. Wildlands Network
5. Arizona Game and Fish Department
6. U.S. Fish and Wildlife Service
7. Arizona Department of Transportation