NRDC: Heavy beetle kill among whitebark pines

CHEYENNE, Wyo. -- Environmentalists who participated in an aerial survey of the Yellowstone ecosystem say beetles have killed vast numbers of whitebark pine trees in Wyoming, Montana and Idaho.

Louisa Willcox with the Natural Resources Defense Council says mortality in some whitebark pine forests is as high as 70 percent. Worst-hit areas include the eastern edge of Yellowstone National Park.

The NRDC filed a petition last year to list the whitebark pine as endangered. The group assisted with the survey in conjunction with the U.S. Forest Service and National Park Service.

Whitebark pines can live more than 1,000 years and grow at higher elevations than any other tree in the Rocky Mountains. Their seeds are an important food source for grizzly bears.