In 1995, the Fish and Game Commission added to the list of endangered species coho salmon in streams south of San Francisco. In 2004, it joined this coho population with coho from San Francisco north to Punta Gorda. Since then, the Commission has included coho salmon south of Punta Gorda in its endangered species list. In this case, Plaintiffs filed a petition asking the Commission to delist coho salmon south of San Francisco from the list of endangered species, arguing that these fish did not qualify for listing because they were not “native” within the meaning of the California Endangered Species Act. The court of appeal denied relief on a procedural basis, concluding that Plaintiffs’ argument attacked the Commission’s final listing decisions in 1995 and 2004 as having no basis and that a petition to delist a species may not be employed to challenge a final determination of the Commission. The Supreme Court reversed, holding (1) a delisting petition may, based upon new evidence, challenge an earlier listing decision; and (2) therefore, the court of appeal incorrectly limited the scope of the delisting petition.