Robbers Roost was a hideout for outlaws and hunted men long before Butch Cassidy found it in 1884. The impenetrable wastes and wilds of this high desert country in southeastern Utah, cut through by canyons along the Green and Colorado rivers and bounded on the west by the Dirty Devil, discouraged lawmen from pursuit. Growing up on a ranch that included Robbers Roost, Pearl Baker heard many of the legends about—and talked to many who remembered—the notorious Wild Bunch. In the 1890s they spread over Utah, Wyoming, Montana, Colorado, and Arizona rustling cattle, stealing horses, robbing banks and trains, and often taking cover at Robbers Roost. Butch Cassidy and the Sundance Kid, Flat Nose George and the Curry boys, Elzy Lay, Gunplay Maxwell, the McCarty boys, Peep O'Day, Silver Tip, Blue John, and Indian Ed Newcomb—they all come to rip-roaring life while courting death in The Wild Bunch at Robbers Roost.

In his introduction to the Bison Books edition, Floyd A. O'Neil, director of the American West Center at the University of Utah, discusses landscape, the law and the Wild Bunch, and Pearl Baker's lifelong preparation for this lively book.