The southern Rocky Mountain wolf (Canis lupus youngi ) is an extinct subspecies of gray wolf which was once distributed over southeastern Idaho, southwestern Wyoming, northeastern Nevada, Utah, western and central Colorado, northwestern Arizona (but north of the Grand Canyon), and northwestern New Mexico. It was a light-colored, medium-sized subspecies closely resembling the Great Plains wolf (C. l. nubilus ), though larger, with more blackish-buff hairs on the back. This wolf was extirpated by 1935. Wolves of the subspecies Canis lupus occidentalis have now been reestablished in Idaho and Wyoming.