Whitebark pine trees are in trouble. Growing in the Western mountains, these important trees provide habitat for small animals and food for grizzly bears. But global warming has driven the mountain pine beetle, a pest that attacks and kills the trees, into the areas where the whitebark's habitat. If measures aren't taken to combat global warming, iconic landscapes and entire ecosystems could be dramatically transformed.

NRDC asked the government in 2008 to consider the whitebark pine for endangered species status, then sued earlier this year because the government hadn't acted on the request. A preliminary finding to be issued Tuesday is expected to move the tree a step closer to federal protection.

Related:
More OnEarth coverage of whitebark pine
Experts on NRDC's Switchboard blog