The trees spanning many of the mountainsides of western Montana glow an earthy red, like a broadleaf forest at the beginning of autumn.
But these trees are not supposed to turn red. They are evergreens, falling victim to beetles that used to be controlled in part by bitterly cold winters. As the climate warms, scientists say, that control is no longer happening.
Across millions of acres, the pines of the northern and central Rockies are dying, just one among many types of forests that are showing signs of distress these days.