A dead pine beetle is shown on the inside of a piece of bark peeled from a beetle-killed tree. Cold winters, lack of food and control measures have caused steep declines in the destructive pine ...

Mountain pine beetle burrow in pine tree bark, releasing a fungus that clogs and destroys the connective tissues of the trees. Trees can die within weeks of an attack.

The melting of glaciers in the Rocky Mountains led to a remarkable discovery: a 5,900-year-old whitebark pine forest, including more than 30 dead trees that were entombed in ice for millennia.