For more than twenty years the Supreme Court has held that a federal takings claim is not ripe until the claimant seeks compensation in state court. The Court's recent opinion in San Remo Hotel, L.P. v. City & County of San Francisco establishes that the federal full faith and credit statute applies to federal takings claims. The Court itself recognized that its decision limits the availability of a federal forum for takings claims. In fact, however, claim preclusion doctrine-not considered or discussed by the Court-may result in more stringent limits on federal court review of takings claims than the Court's opinion anticipates. The counterintuitive result-that federal takings claims must be litigated in state court-plays a critical role in the Supreme Court's emerging takings jurisprudence, which largely delegates to state courts the primary responsibility for policing land use regulation.