ak!
I know snakes are important to the environment
but
ak!

We once had a ponder here from Louisiana
who caught a water snake with a minnow trap.
You have to use a live fish :-( and you might
have to build one big enough, or remodel one,
to get a snake that big.
She left some of the trap above water so the
snake would not drown and then she relocated
it.
And I found this on the web
http://www.insectimage.com/Gallery%2017/trapset2.html

good luck! And let us know what happens.

kathy :-)