As of this writing (Aug. 2002) this fine book is out of print, and shouldn't be. It is an informative and well illustrated survey covering almost 200 years of pictorial representations of the American frontier.
Because of my interest in the mythology that developed around the cowboy, I found the chapters on Frederic Remington, Charley Russell, and Buffalo Bill Cody especially absorbing. Magazine illustrators who further developed imagery of the "wild west" are represented here in discussions of N. C. Wyeth and Maynard Dixon.
On a parallel track, the authors give a chapter to the early silent Westerns, highlighting the careers and contributions of Tom Mix and William S. Hart (a precursor of Clint Eastwood). Another chapter is devoted to the Hollywood Western during the sound era noting similarities between Remington's imagery and that of director John Ford. There's also a discussion of the evolution of western movie themes from "The Virginian" (1929) to "The Ballad of Cable Hogue" (1969).
This book is a rewarding study of the American West as its visual artists inspired the imaginations of people around the world. Definitely worth having.