Moin,
auf der Internetseite der Grand Canyon Railroad findet man folgende Info: “When you book a Grand Canyon Railway package on the Internet, National Park Service fees are automatically included in the cost. If you already have a pass, you will be reimbursed the fee by presenting your pass at the ticket counter in Williams. If you have a National Park Pass and believe that you are entitled to a refund you will need to present your NPS card to the Grand Canyon Railway depot upon arrival.”
Gruß,
Peter