Current discounts end on 5/24. You do not need the pass in hand to make reservation at the passholder's rate.
You may be required to show your pass/voucher at check-in.
You will need to pay a deposit of 1st nights room and tax and balance upon check-in.
Beware of the cancellation policy. The website said 6 days when I reserved, but a 2nd reservation showed 45 days or no refund.