Paleontological evidence shows that Jaguars likely occurred in much of California, and even as far north as Washington State. Specific evidence of Jaguar remains (bones and fossils) indicated that they certainly were found in the southeast Bay Area, the South Coast Range southward through the Los Angeles basin, and east into the western deserts of southern California, as well as along the Colorado River drainage between California and Arizona. Historical evidence, around the time of the European invasion of California, includes direct observations of Jaguars from San Francisco to San Diego, and along the Colorado River drainage. Although no Jaguars exist in the wild in California today, at least 8 individuals have been found in Arizona, within their dispersal distance to California. This suggests that some potential exists for one or more dispersing Jaguars to cross into California, from Arizona or Mexico. Recent suggestion of reintroduction of large predators has prompted consideration of reintroduction of Jaguars into the southwestern United States. However, the first conversation must include careful consideration of the individual animals that may enter southern California and the 25 million people that currently live there. I suggest that the California Department of Fish and Wildlife consider the potential for dispersal of this species and make plans to protect any Jaguars that cross into California.