This picture doesn't provide the perspective you might get if you were trying to run from it and you were just outside the frame of this shot. A mature male gray wolf can weigh up to 200 pounds; a female closer to 140 or 150. Their teeth break bone and go through flesh as if it was butter with a chase speed of about 35 miles per hour.
A wolfpack typically hunts together and each wolf lunges in to rip away something from its prey to eat on the hoof -- a warm smorgasbord. Death is painful for the victim that usually hemorrhages out or receives a lethal bite to the throat at some point.
What is it like being jumped on by one? I can only imagine that, with the backing from a pack, it would be fearless and therefore everything would be thrown into the fray. Two hundred pounds of speed and muscle could take a human out in short order, considering the animal knows all of the weaknesses to go after since it has hunted its entire life. It has paws at least half the size of a human's foot and lethal, slashing and grabbing claws.
Perhaps that is a big reason why the various tribes honored and respected the wolf as something special -- even spiritual. As you can imagine, though, there is a battle happening between ranchers and hunters and some of the tribes. Since the reintroduction of the gray wolf, there is fear that the animal will decimate livestock and wild game alike, impacting two major industries. Many tribes and ecologists see the wolves as a necessary component to keep nature in balance. I deal with some of this question in my future novel, "The Sheep Eater."
Still others argue that the gray wolf was introduced in place of the original smaller timber wolves. The debate is not going to end any time soon, although some states have begun hunting seasons for wolves. It seems to me that we have had similar experiences with the grizzly bear and the bison in years past, almost to the point of extinction.
It is worth your time to learn more about. There have certainly been more grizzly bear-related human deaths than wolf-related deaths in their respective ranges. Is there room for nature here?