I have already had a bad experience with my resident muskrat - his burrows have caused cave-ins 12' from the old pond that will swallow a mower wheel.
Around bere I have seen snappers butI think the painted turtle is the most common.
Norm - I assume spiny softshells would like it here in Ohio as well as SD? Where did you get them? Do I need to leave some bank with no fence to allow them some burrow space? Any idea how deep any turtle might go to burrow? My fence is 6' - could they make it below that line? I am pretty sure the mrats wont.
I saw the muskrat in my new pond already - this winter when the ice was on. I could see him swimming under the ice. But there will be 4' more water to go so his existing burrows should be too deep.

2/3 acre pond 12 miles from that big pond we call Lake Erie.