It's a national park. The wolves are supposed to be there. Along with the black bears, grizzlies, and cougars.....I agree with Teslin_ that this is statistically not a big deal. ..... The real hazards in winter are icy trails, avalanche terrain, and the usual suspects such as hypothermia. .....(As for the concept of dogs on national park trails as a whole, well, I will only say that I leave mine at home and encourage others to do the same.)