Researchers have captured footage of these bears making a wide range of vocalizations during their most intimate moments—the ...

The valley stretches on for miles. A dramatic world of canyons, plains, river basins and forests as far as the eye can see.

The Sierra Nevada, once a tranquil stretch of towering pines and snow-capped peaks, is now a stage for a new kind of ...

EDITOR’S NOTE: This story is a collaboration between The Associated Press and Grist.