This is the first book in the Secret Journeys of Jack London series.
Jack's 17 and definitely an adventurer. He's on his way to the Yukon River in Alaska, and the gold rush that's going on there. This trip isn't for the faint at heart--on the way to the river Jack comes across dead horses and men, and others who have already turned back. Jack meets two men on his way--Jim and Merritt--and the three spend the winter together, surviving and waiting for their chance to look for gold.
Things are not as they seem. Jack sees a wolf tracking him in the forest several times, and that wolf seems to save his life at different points during his journey. Jack, Jim, and Merritt are all captured by slavers and "pressed" into service, looking for gold. Their camp is attacked by a Wendigo--a supernatural beast. Jack survives, but barely, and is rescued by a forest sprite who also tries to imprison him. Jack has to use all of his wits and some desperate attempts to save his life.
The first in a series, some of the action is a little over the top. The characters aren't developed as much as the scenery and the action. I haven't read any of Jack London's books, so I may not see how alike or different they compare. The last half of the book went quickly. Getting there took a bit of work.