As is the case with most fish, people will spread them. Snakeheads are just taking hold in the Potomac and as they become a common catch, people will start transporting them to other drainages. It is only a matter of time. First it will be adjacent rivers and soon, someone will catch 4 or 5 from a distant state and say hey I'd like to fish for them closer to my home and the rest will be history.