Refusing to follow in his father's footsteps, young Gilbert (Gopher) Piddington rebels at every turn only to find himself in hot water. Through his many adventures he carries his father's natural boxing ability and his mother's keep shooting eye, both of which get him into trouble. Gopher's fascination with steam engines is ignited on his tenth birthday when his English grandparents shipped a miniature model of the popular Double Fairlie workhorse locomotive. He learns a real Fairlie steam engine is working somewhere on a Denver & Rio Grande line. At fourteen, Gopher makes plans to run away to Colorado and become a railroad man, much to his parents' dismay.