Chelydra serpentina (Snapping Turtle) subspecies?

[Peter Zimmer]

Our Munich based organisation has aquired an American Snapping 
turtle (Chelydra serpentina) that was found in the wild.  Since snapping 
turtles are not indigenous to this region and can not be released we are 
interested in returning this fine healthy (and sometimes rather snappy) 
specimen to its proper habitat.  We are wondering if there is some one out 
there who could help us or knows some body who can, differentiate which 
subspecies this turtle belongs to and to what geographical area it is 
indigenous.

I (and the turtle) would be very grateful for any information that can help us 
further. 

Peter Zimmer
Earth Life Shelter Association
Munich, Germany