The Grizzly Bear, Ursus arctos horribilis, is a subspecies of brown bear found in North America.  Brown bears originated in Eurasia and travelled to North America about 50,000 years ago, and into the contiguous US about 13,000 years ago.  It didn’t take long for European hunters to wipe most of them out and three other subspecies which were in California, Mexico and Labrador are now extinct, as a result. There remain only 1500 in the lower United States or about 1 per 221,000 humans. They have a hump at the shoulders that the Black Bear lacks, and their claws are longer, adapted for digging.  – Wikipedia