Zenas Leonard was a wilderness explorer who journeyed across and charted the perilous Rocky Mountains in the early 19th century, keeping this diary as he went. Embarking on his spectacular journey with a company of seventy like-minded fellows, Leonard chronicles the many perils and trials the group encountered through their lengthy voyage deep into unknown territory. The band of explorers are beset with difficulties; the harsh, craggy lay of the land, ferocious creatures, and the various Native American tribes put the men through the greatest physical and mental tests. Many members of the group were fur traders by profession; in scouting the vast landscape of the Rockies, they hoped to discover new and prized game to catch. However their ambitions are sorely tested by hunger and thirst, while dangerous creatures such as the grizzly bear strike terror in their hearts.