They range from Southern Florida all the way north into Canada on the east and as far west as some of the Mississippi tributaries. There is one notable exception the the entire east coast of the US currently within the native range of the Bowfin.
Although there is fossil evidence of the Bowfin in Maryland, Delaware and the District of Columbia within the past three decades, but have reported no documented catches of Amia Calva in many years. It is most likely an unrelated "strange coincidence", but these three areas are those which the somewhat similar looking "Invasive Snakehead" that has fully established breeding populations in these three states/ districts.
Again probably a coincidence, but where the Snakehead have most successfully established themselves, the bowfins have mysteriously abandoned the local! It is not like the Bowfin is a seriously "migratory" fish.
It may have nothing to do with the Snakehead, but Bowfin do not relocate hundreds of miles by nature. Something has succeeded in driving the Bowfin from Maryland, Delaware and D.C.