Thirty-one grey wolves from Canada were turned loose in Yellowstone in the 1990’s

August 11, 2011: The Ottawa Citizen

Thirty-one grey wolves from Canada were turned loose in Yellowstone in the 1990’s. The canines were soon tearing after elk in the U.S. national park, which had not seen wolves in 7 decades. Aspen, willow and cottonwood trees have begun to sprout now that the elk are in check.