This work explores the legendary 19th-century California bandit Joaquin Murieta as he is manifest in the history, literature and folklore of the West. The first section of the work examines in some detail the historical milieu which gave rise to widespread banditry dur~ng the California gold rush, at which time Murieta is said to have been active. The second section traces the development of the literary hero Joaquin Murieta from his creation by John Rollin Ridge through a number of American, Mexican, Chilean, Spanish and French incarnations. Section three similarly traces Murieta as a folk hero through a cycle of legends perpetuated by California's Anglo-American folk community. Section four of the work returns to history, examining in some detail the evolving relationship between California's Mexican-American and Anglo-American populations in the century following the gold rush. The fifth section explores Murieta's development and perpetuation as a folk hero in the~ Mexican-American folk community. The work's final section examines some dynamic mechanisms at work in the evolution of Murieta folk lore, and suggests some directions for further study.