I wanted to write this review to help with some of the confusion. I've been there and back but sometimes I am still confused by this park.
You will want to know that they have more than one campsite (Linesville and Jamestown).
They also have more than one beach. The smaller beach is where you can access a bathroom. The larger beach seems to have been forgotten to a degree as no bathroom.
Then next door in Ohio they have the same name for their park. Grab all of the paper maps from Ohio and PA. As on Google Maps it does get confusing as to which part is in Ohio and which part is in PA. Notice that the parks ignore their neighbor to a degree which adds to the confusion.
Be sure to visit the Pymatuning Dam Gate House (Which feels like a whole different park).
We did find some trails around the Pymatuning Dam Gate House but had trouble finding trail maps or folks to ask for information.
Make sure to go over and feed the carp. This is located at Linesville Spillway and not in the Linesville campground. I will see if I can upload the carp video as it was a neat experience. Do bring bread as they do not have the fish pellets for purchase at this time. Bread is bad for the water and ducks etc. but at this time they are not discouraging it.