I caught a 7lb hudd fish somewhere between 65-70'once. I thought I was casting in to about 50' of water but the line just kept spilling off the reel to an absurd depth. One crank and it felt mushy and the fish was on.

The deepest fish I've ever caught was at Don Pedro, drop shotting, at around 75'.

I've read interviews with Aaron Martens where he's talked about catching bass over 100' deep. I would imagine this is a localized phenomenon on certain clear, deep lakes--and very likely the fish at this depth are un-pressured, if they are fished for at all.