The American West is a region vast in territory, history and inhabitants, and in this book the author of The Frontier Years and Before Barbed Wire has covered a considerable section of it. His ""Yellowstone"" is the entire Yellowstone valley: the river itself, its tributaries, their tributaries, and the country through which they flow, as well as regions seldom considered as a part of the Yellowstone system, such as the Upper Missouri and the Hole-in-the-Wall in Wyoming. Nor are the author's ""plainsmen"" the ""inhabitants of plains"" of dictionary definition; they include almost everyone who ever saw the Yellowstone, from 18th-century explorers to 20th-century cattle rustlers. It is an impressive parade: Lewis & Clark; trappers, artists; scientists; Kenneth McKenzie, ruler of great Fort Union near the mouth of the Yellowstone; Father De Smet and Jim Bridger and the fabulous Sir George Gore; prospectors, bandits, cowboys, soldiers,- one of them named Custer. And always, of course, Indians, growing more hostile with the years: Red Cloud and Sitting Bull, Crazy Horse, the Ghost Dancers, and endless others. Unevenly written and awkwardly arranged but containing much fascinating material, this book, too heavy for casual reading, should appeal to Western ""buffs"" and writers of ""Westerns"" of all kinds. Professional historians will deplore its repetitions and minor inaccuracies, but will value it for its quotations from little-known sources and for its excellent bibliography.