If you want a specific shelter on a specific day, then I recommend paying for a reservation. It's a good way to make sure the "first come first serve" rule doesn't apply. If someone else already reserved a certain shelter, then it'll have papers posted telling others that it is reserved. If you don't want to pay AND it isn't reserved for the day, I recommend you be there first.
I don’t think you need to pay for shelters. I believe those are first come first serve.
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