Doc,
I am also located in NE Iowa and have a pond similar to what you describe, only a little smaller at about 1/2 acre. I am approx. 25 miles north of Cedar Rapids. I had a pretty healthy snail population a few years ago and debated the RES too. I ended up stocking some. I have never caught one of them, but have not really fished specifically for them. I am pretty confident some have survived though because I do not have any snails in my pond now from what I can see. I purchased mine from a fish hatchery in West Union, Iowa and they came from Arkansas.
