Nature series documenting the return of one very special wolf pack to the snowy peaks of Washington's Cascade Mountains - the first to return to the American Northwest in 70 years. 　　Part 1. 　　At a time when wildlife is disappearing across the planet, one animal is making a comeback - the wolf. Wolves were wiped out across much of America, with more than a million wolves estimated ... (展開(kāi)全部)