Amazon.com Product Description (ISBN 0531151093, School & Library Binding)

Once, North Hill was the commercial and social center of Piketon, a growing city in the Rocky Mountains. Now it's a place of boarded-up stores and roaming gangs.
But even-deadlier predators have arrived . . .

URSUS

Local residents have been disappearing for weeks, and the city's political elite blame wild dogs. But a local zoologist suspects another cause--mutated bears, small in size but intelligent and immensely strong, that have come down from the mountains to hunt in packs.