Historically, black wolves have been hunted and driven nearly to the point of extinction but they aren't the only wolves at risk. Black wolves are actually a type of gray wolf the name of the species is a misnomer, as gray wolves are sometimes born black because of a genetic mutation.
Black wolves (gray wolves) in the western US usually weigh between 60 to 120 pounds (27-54 kg) with adult males taking up the higher end of the spectrum. They stand 27 to 33 inches in height at the shoulders and measure 60 to 72 inches in length. A wolf’s tail is long and bushy and usually carried down or straight out, but never curled. Despite their large stature, gray wolves and other wild canids are typically very lean animals and carry very little body fat, Biologists who have handled and weighed more than 250 wolves over the last 25 years throughout Montana, Idaho, Wyoming, Washington and Oregon report that few wolves weigh more than 120 pounds and the largest wolf they handled was a male who weighed 144 pounds. The largest breeds of domestic dogs are reported to weigh more than 180 pounds.
Today, gray wolves have populations in Alaska, northern Michigan, northern Wisconsin, western Montana, northern Idaho, northeast Oregon and the Yellowstone area of Wyoming. Mexican wolves, a subspecies of the gray wolf, were reintroduced to protected parkland in eastern Arizona and southwest New Mexico. The historic range of the gray wolf covered over two-thirds of the United States.
Wolves are generally feared along with their tendency to kill domesticated animals and livestock, made them a target for hunters. In some cases, eradicating wolves was sanctioned by local governments, which rewarded hunters with bounties. By the mid-20th century, the worldwide wolf population was down to about 200,000, when it had once been in the millions.