"Desert Ecosystem Caught in Crossfire of Immigration Battle"

"PALOMINAS, Ariz. -- The San Pedro River is idyllic on a mid-August morning, with tall cottonwood trees creating a shady respite from temperatures already into the high 80s and muddy banks pocked with animal tracks.

But the towering metal fence that ends less than 50 yards before the river, and a series of Normandy barriers largely hidden in the tall summer grass, serve as a reminder that this isn't a typical conservation area.

It's a battleground.

The San Pedro Riparian National Conservation Area, which stretches across 57,000 acres of public land including this spot at the U.S.-Mexico border, is at the heart of a long-running fight involving environmentalists, federal agencies and Congress over how to control the nation's nearly 2,000-mile southern boundary."

Jennifer Yachnin reports for Greenwire September 8, 2014.