Researchers are concerned the declines will lessen the scale of and in some cases possibly eliminate the large saguaro forests in Arizona.

An unusual pattern of tiny rock tunnels, first found in Namibia's desert roughly 15 years ago ... No known chemical or physical weathering mechanism can explain the phenomenon.

Weathering and erosion slowly chisel ... tumbling boulders high in the mountains to sandstone arches in the parched desert to polished cliffs braced against violent seas. Water is nature's ...

A heat wave is expected to hit Southern California and the High Desert from Wednesday to Friday, with temperatures reaching the high 80s and low 90s. The Low Desert, including Palm Springs ...