A previous study suggested that the genomes of the arenaviruses native to North America are a product of genetic recombination between New World arenaviruses with significantly different phylogenetic histories. The purpose of this study was to extend our knowledge of the principal host relationships and evolutionary history of the North American arenaviruses. The results of this study suggest that the large-eared woodrat (Neotoma macrotis) is a principal host of Bear Canyon virus and that the present-day association of Bear Canyon virus with the California mouse (Peromyscus californicus) in southern California represents a successful host-jumping event from the large-eared woodrat to the California mouse. Together, the results of analyses of viral gene sequence data in this study and our knowledge of the phylogeography of the rodents that serve as principal hosts of the New World arenaviruses suggest that genetic recombination between arenaviruses with significantly different phylogenetic histories did not play a role in the evolution of the North American arenaviruses.