FLAGSTAFF — Beneath the scenic yellow and red leaves of soaring aspen trees in the Kachina Wilderness, forest ecologist Mike Stoddard is looking down. His concern isn’t the brilliant fall foliage but ...

Aspen forests help slow the spread of wildfires and could serve as fire breaks in Colorado and other southwestern states, according to a peer-reviewed study by Western Colorado University researchers.

DENVER — Something is killing the quaking aspen trees of the Rocky Mountain West. The slender, white-barked trees that paint the hills gold every autumn are dying, some scientists say, leaving bald ...