Down hear in the south east it is tough to find a site that is somewhere you want to go. All the state parks at the beach are booked solid. Very few sites available at parks on the lakes, and the ones that are available are not lakefront.
I lucked into a cancellation at a state park in the mountains after checking for cancellations twice a day for 2 weeks.
State parks at the beach in FL you pretty much have to get 11 months ahead of time, or find a cancellation.
I know lots of people book a bunch of sites, but know they won’t be able to use them, and end up canceling. I have not done that, but I’m thinking about doing that.
