As a boy I used to love books like this, about untamed nature and woodlore and woodcraft, but it has been many years since I've read them. I recently had the occasion to revisit this excellent novel, and found that it has aged quite well and is still a terrific read.
The story has to do with a wolf named White Fang, and begins before he was born, with his father and mother leading a pack in the dead of winter in the frozen Canadian wilderness. There is no game around and all are starving. They harass and harry a beleaguered dog-sled team over the course of several days, picking the dogs off one by one, then finally surrounding the one remaining man. He builds a ring of fire to protect himself from these ravenous wolves, but knows he soon must succumb to exhaustion. He notices the she-wolf, sitting patiently outside the ring, seemingly indifferent--except for the string of drool coming out of her mouth in anticipation of making a meal out of him.
That is the lesson here, in this story of White Fang. It is a savage world, a world in which you either kill or are killed, eat or are eaten. His first day out of the den he kills and eats a small bird, then in turn is almost eaten by a hawk. He observes a porcupine roll itself into a ball to defend itself against a lynx, then observes the lynx yowl in pain after foolishly getting stung. The lynx plays another prominent role. Trying to survive a typical lean winter, White Fang's mother takes the desperate step of going to the absent lynx's den to eat its offspring. The enraged lynx later comes to their den and attacks, but with the help of a growing White Fang, they defeat it. It also becomes a meal.
White Fang eventually gets taken in by men, first an Indian tribe where he is "tamed" with brutality, then by white traders who use him for their own base purposes. Through it all we see the cruel world in which he lives and feel his pain and hunger and anger. It is a well-plotted adventure carefully observed, and serves as a great reminder of how savage the untamed wilderness is, and that mankind is often only a bare step above it.