Buck is a dog living a good life on a ranch in California with his master, Judge Miller, until he is stolen and sold to pay off a gambling debt. He is taken to Alaska, where he falls into the hands of two Canadians caught up in the gold rush, who train him as a sled dog. The harshness of the environment forces Buck to reclaim his wild side, which is the only way to survive in the cold northern lands.

Jack London spent nearly a year in the Yukon (Canada) gathering material for the book. The story was serialized in the Saturday Evening Post in the summer of 1903 and published in a single volume a month later.

The transformations of the animal, the portrayal of the people seeking the yellow metal, the description of the landscape, and the perfect tracking of the sequence of events justify the characterization of the prose as a bestseller of all time.

The great popularity and success of the book established London's reputation. Much of the charm of this novel stems from its apparent simplicity and the intense emotion that this survival story conveys.