A chronological survey traces the gradual opening of the American West, recounting early sea and land approaches and the successive explorations that pushed the frontier. The narrative emphasizes the roles of trappers and traders in trail-breaking and situates their exploits alongside well-known expeditions and individual explorers. Interwoven with exploration history are chapters on the region's wildlife, Indigenous peoples, and the social consequences of contact, including sharp criticism of the liquor trade. The author supplements research with personal travel experience, maps, illustrations, and sketches to clarify routes and events.