campsite availability--tent camping w/o reservation at the state park

[Flyfisher for men]

I may be in the area the last week of July and was thinking of hitting the trout water.

I'd be coming in late afternoon/early evening on a Sunday and maybe stay Monday night, too.

How likely is it to find a campsite in a busy park like that without a reservation? I don't need electricity, just a place to pitch a tent.