Director of the Department of Revenue of Montana v. Department of the Treasury

(1) Whether the federal savings bond statute and regulations impliedly preempt longstanding state unclaimed property laws, where the statute and regulations are wholly silent on the treatment of unclaimed bonds and where Congress has expressly preempted state unclaimed property laws in numerous other contexts; and (2) whether application of state unclaimed property laws to unclaimed U.S. savings bonds owned by state residents violates the intergovernmental immunity doctrine, where these laws reflect the states" exercise of constitutionally reserved escheat power.