IOWA ACADEMY OF SCIENCES. 
39 
HOW OLD IS THE MISSISSIPPI? 
BY FRANCIS M. FULTZ. 
(Abstract ) 
In asking this question it is not intended to open for discus- 
sion when and how each particular part of the great river came 
into existence. Nor will it be expected to prove whether or not 
it is now everywhere following the course it first selected for 
itself. But the effort will be to show that its prototype must 
have existed at a certain fixed time in the distant geologic past. 
In fixing this date it must be understood that the claim is not 
made that the river course surely dates from that time, but that 
it existed at least as early as that. It may be much older, but 
as for that let future discovered evidence tell. That part of the 
Mississippi to which the evidence in question pertains, lies 
between the mouths of the Iowa and Des Moines rivers. 
The evidence set forth goes to show that the present Missis- 
sippi drainage system existed as early as the beginning of the 
Upper Burlington epoch; and that, although interrupted by 
frequent and perhaps prolonged submergences, it nevertheless 
still remains practically the same. 
