My family and I were camping at Tionesta last month and we decided to swim in the river (Tionesta river I believe) where the beach was located. It is now closed. It's near the Allegheny river. We finshed swimming and my young daughter said she had a bug on her foot. I took a closer ook and discovered it was a leech. Have you ever removed a leech from a frantic 8 yr old? That's another story. Also, found a small one between her toes. So I know there are leeches there for sure.