 During his youth, Siringo had ridden the range in eastern New Mexico and the Texas Panhandle, the familiar haunts of William Bonney and Pat Garrett, and knew both of them.In 1920, he published a sympathetic biography, "History of Billy the Kid", in which he described the daily life of a cowboy realistically, but romanticized his account of Bonney with fantasies and exaggerations—its title page claimed "His six years of daring outlawry has never been equalled in the annals of criminal history.