Read it through once

But no living man had looted this treasure house, and the dead were dead; wherefore John Thornton and Pete and Hans, with Buck and half a dozen other dogs, faced into the East on an unknown trail to achieve where men and dogs as good as themselves had failed. They sledded seventy miles up the Yukon, swung to the left into the Stewart River, passed the Mayo and the McQuestion, and held on until the Stewart itself became a streamlet, threading the upstanding peaks which marked the backbone of the continent.