Parts of the northern US are the southern end of their range. They live in areas of several northwest states, but my only encounters have been in Yellowstone. They're really tall, make a Great Horned owl look squat. The first one I ran into was sitting on a waist high stump no more than 50 feet away. I had stopped to rest and didn't pick him (her?) out initially. Enjoying the quiet for perhaps a minute, I nearly came out of my skin when I met the eye-level gaze of this big gray forest shape. The owl gave me 10 or 15 seconds and silently filtered away through the trees.