Idk about swimming. I've never tried in the lake,, but the beach seemed pretty nice when I went. Just make sure you stay on the main path when you get there. It goes behind the 2 buildings from the parking lot towards the lake.
Currently the main entrance to the beach is closed. It was washed out last year and they have not finished repairing it. You have to go over the dune path to get to the beach.
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