Talk to the park hosts. Your spot might be reserved though.
Just fill out another yellow envelope and put another night's fee in it. Drop it in the remittance box and you're good to go. You don't need to reserve a year in advance. There are first come, first serve spots that are not subject to reservations. If you reserve online, you must reserve at least four days in advance.
You need to reserve your spot and the days you are staying one year in advance.
Thanks! Your answer is awaiting moderation.