Report 51902: Strange encounters and possible tracks found in a swamp near the Douglas State Forest

On May 8th 2016 I was riding my four wheeler over on Fort Hill road in Oxford Webster area in the woods. I just hanging out by a swamp clearing a trail and had a weird feeling where something was watching me. My back was turned to the swamp and I heard a small splash coming across the swamp and didn't really think nothing of it. About thirty seconds later I heard another one and that one caught my attention but I didn't see it. It was bigger and it was in the middle of the swamp. So I dialed my buddy and as he picked up the phone, a rock about the size of a football, if not bigger was thrown about three quarters across the swamp and I saw this one hit the water.