Scene near Granby, Colorado with beetle kill on the mountain sides and wild flowers in the foreground. Mountain pine beetles appear to be doing more than killing large swaths of forests in the Rocky Mountains. Scientists suspect they are also altering local weather patterns and air quality. When portions of a forest die, the local atmosphere can change in subtle ways. BEACHON, an international field project is studying a region extending from Wyoming to northern New Mexico to determine a forest's impact on the atmosphere.