One of only three white wolves roaming Yellowstone National Park has been put down by park staff after it was found with severe injuries, reports the AP. Hikers found the female wolf Tuesday on the north side of the park, says PJ White of the National Park Service. White says the wolf was in shock and dying, leading to the decision to euthanize it and investigate what caused the injuries. The nature of the animal's injuries could not immediately be determined. The predator was one of three known white wolves in the park. It had lived to 12 years, twice the age of an average wolf in the park, and was one of the most recognizable and sought after to view and photograph by park visitors. (More Yellowstone National Park stories.)