Consolidation Coal Co. v. United States

Whether, when applied to coal that is eventually exported, the Surface Mining Control and Reclamation Act of 1977's Abandoned Mine Land fee - which by regulation is not assessed and collected until the time of first sale, transfer, or use of the coal - violates Article I, § 9, Clause 5 of the Constitution, which provides that "[n]o Tax or Duty shall be laid on Articles exported from any State."?