Bull sharks can tolerate freshwater, they have been reported to live in lake nicuagra. The story from deep creek lake is, I think, a hoax. I was living in Annapolis when that supposedly happened, and I was very much into sharks and fish. I would have heard of it, and there would be another source available, but their isn't. I have fished that lake many times, and read a great deal about it, and never heard any mention anywhere of a shark being caught there. That being said, Bull sharks are reguraly caught in the freshwater areas of the cheasapeake bay and it's tributaries. We lived on the south river, just below annapolis. I saw a shark near the headwaters of beards creek, feeding on carp. What a sight, scared the pants off me, and nobody believed me. Oh well.