Yup, it happens a lot imop. Most of em I have seen look 90% wolf. Cant tell em apart much. Been going on in W Wa for decades. They do run away and roam sometimes come back. As a kid an old farmer had a 50/50 female. It ran away for 6 months. Came back whelped litter under front porch then left few months later. He kept a male pup. Gorgeous dog. Big smart, athletic unreal. BUT if you weren't a friend or an Alpha person you were in trouble! Not a good family dog imop. I don't know how time went as I was done working and we didn't hay his land after that. Adna/Bunker area. His female breed with a wolf type dog in the hills but who knows what exactly?? The PUP was 100+lbs, tall and looked like pure wolf to us.