Do I need to make a reservation?

I would

After school starts you can probably show up and get a site.

Generally it's a good idea. Summer/peak season it's rare to get a spot unless reserved ahead of time, but during the off-season, there do tend to be some open sites, especially during the week.

Yes.

Reservations here are recommended do to popularity. Excellent place!

Call Thursday and Friday a few times because they always have cancellations

I would they accept reservations up to 9 months in advance really nice park