Top Ten Most-Endangered Public Lands

Air and water resources are seriously threatened at South Texas's Big Bend. Scenic views? Forget it: They're often fogged out by air pollution, particularly in summer. According to Environmental Protection Agency and Park Service studies, some of the worst pollution comes from coal-fired power plants that lack modern emission-control technology.

In addition, the Rio Grande faces low flows, which concentrates water pollutants, undermines ecological health, stresses wildlife, and threatens recreational rafting. The low flows are partly a result of water diversions in large, urban areas like El Paso. And on the Mexican side, flows from the Rio Conchos tributary have declined by 50 percent.

Recommended solution: Clean up dirty power plants in Texas and Mexico, and establish guaranteed minimum river flows in the Rio Grande through the park.