Environmentalists and farmers are challenging Arizona's approval of an air pollution permit for Copper World Mine, claiming ...

The desert city in southern Arizona is a sanctuary for stargazers—and now it's even easier for visitors to explore.

The committee also voted in support of two bills that would allow groundwater pumping regulations in protected areas to be ...

The result is that the federal Colorado Basin River Forecast Center is now predicting that April through July flows into ...

Many water officials have seen cloud seeding as one possible fix for the U.S. West's extended drought, but a new federal ...