The gray wolf or grey wolf is also known as the timber wolf or western wolf. It is a canid native to the wilderness and remote areas of Eurasia and North America. It is the largest extant member of its family, with males averaging 43–45 kg (95–99 lb), and females 36–38.5 kg (79–85 lb). Like the red wolf, it is distinguished from other Canis species by its larger size and less pointed features, particularly on the ears and muzzle. Its winter fur is long and bushy, and predominantly a mottled gray in color, although nearly pure white, red, or brown to black also occur.

Gray wolves were once common throughout all of North America, but were exterminated in most areas of the United States by the mid 1930s. Today, their range has been reduced to Canada, Alaska, the Great Lakes, northern Rockies and Pacific Northwest. Thanks to the reintroduction of wolves in 1995, Yellowstone National Park is one of the most favored places to see and hear wolves in their native habitat.

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