From a veteran historian of the West, a fine account of early American explorers, a unique group of men who ""could be led but not commanded."" The mountain men, Utley (The Lance and the Shield, 1993) writes, were a ""mostly illiterate"" bunch of rough-and-tumble entrepreneurs, given to gaudy dress, drunkenness, and, often, mindless violence. Yet over the first half of the 19th century they collected a vast amount of information on the geography of the West, blazing trails across the high plains, the Rockies, the Great Basin, and the Sierra that would eventually bring Anglo settlers across the Mississippi into newly conquered territories. They went, Utley writes, less from noble motives than ""to make money in a pursuit that promised adventure, excitement, personal freedom."" Still, some of these mountain men were, in Utley's view, aware of their importance to the historical moment: Working to thwart Spanish, French, British, and Russian designs on the vast region, they foresaw that their explorations would open the West to the claims of manifest destiny. Utley offers excellent descriptions of Jim Bridget, John Charles FrÃ¢mont, Jedediah Smith, Benjamin Bonneville, Joe Meek, Kit Carson, Old Bill Williams, and Joseph Walker. He also writes easily of what might be called mountain-man culture and dispels a few myths, especially the notion of the trapper-explorer as lone wolf: The mountain men traveled in groups of 40 to 60 men, Utley writes. To ""wander in lonely solitude. . . would have been suicidal."" Despite their caution, many mountain men died violently, killed by Indians or fellow trappers. Some went gently into history; Utley writes poignantly of Jim Bridger, who became a trader of beaver pelts, horses, and seashells, the last of which ""he did not know how to value."" A broad, vividly written work of historical reconstruction.