Joe becomes embroiled in a Tom-Horn-esque range war between extreme environmental activists and wealthy millionaire "ranchers." Savage Run is the name of a canyon wherein a Cheyenne tribe outran and out-maneuvered their Pawnee enemies. Joe and the environmental activists he's trying to save come across it in their flight from the man who has been hired by the Stockmen's Association to kill them.

Worst part of the book, though, is that his buckskin mare Lizzie dies.