Scientists say in a new study that the return of gray wolves has dramatically altered the landscape in portions of Yellowstone National Park by curbing foraging elk herds that prevented new aspen, willow, and cottonwood trees from taking root.
Wolves were reintroduced to Yellowstone in 1995 and 1996 after being killed off early last century.
(READ the AP story in the Kansas City Star)
RELATED (2006): Reintroduction of Wolves an Environmental Success