This 1972 film adaptation of Jack Londons classic story stars Charlton Heston and Raimund Harmstorf as government mail carriers working in the hostile environment of the Yukon during the 19th. Century Klondike gold rush. During this time demand for good sled dogs was high, this is the story of Buck, a domestic pet stolen from a California ranch and sold to work the Skagway to Dawson City route pulling mail and supplies and the effort to adapt to his harsh new life.