Arthur Lakes's field journals vividly capture the excitement of unearthing the enormous vertebrae, femurs, humeri, ribs, teeth, and claws of apatosaurus (brontosaurus), stegosaurus, and allosaurus as well as the bones of other Mesozoic-era creatures. Lakes's descriptions of the stratigraphy of the Wyoming quarries have allowed future generations of geologists to locate them within the Jurassic Morrison formation.

A reflective and wide-ranging naturalist, he also evokes the grandeur of the Rocky Mountain and Plains landscapes, noting the details not only of rock formations and fossils but also of a rich variety of plants and animals and illustrating his accounts with sketches and watercolors.

The journals also recount the dangers and hardships of scientific research in territories where Indian conflicts still raged, outlaws plotted train robberies, and cave-ins or avalanches could obliterate weeks of work. Complete with sidebars that supply information on such related topics as the Florissant Fossil Beds and the Ute War, the book conveys the true adventure of early dinosaur discovery on the western frontier.