Caught a nice Brown on lake Monona at the mouth of Starkweather creek 20 years ago. Also caught a small Brown on The wisconsin river by Portage 15 years ago.
Story creek caught a small northern, Bluegill and a small Walleye over the last few years, all during high water.
A few years ago on opening day following a decent flood I went out trout fishing and came back with 10 nice perch. I caught a few trout to but I figured the perch don't belong and there tasty. I've also caught a few northerns, channel cats, pumpkinseed, and bullheads its amazing what is in some of these trout streams. All of these fish came out of holes that usually hold brookies and the odd brown so its fairly cold water anyway.
In a pierce county trout stream (pine creek) I caught three large mouth bass (4") this spring. I also just recieved word that someone caught a 23" brown trout by the Lake City, MN marina on Lake Pepin (Mississippi River).
my aunt and uncle have a piece of land in western wisconsin. for years there was a dry creek bed in their land, awesome pheasant hunting but bone dry. we had back to back monster floods and the following spring water was running out of a nearby hill flowing into the creek bed, making it a creek, albeit a small creek, again. we were out there one may day and i had a fishing pole in my car and i dug up a couple worms and threw in into a small pool, caught two brook trout out of that pool that day. the nearest trout stream was miles away and the previous fall there was no water at all in this bed and 4 months later i'm catching brook trout in it, i thought it was crazy but shows how much trout can travel.
Caught a small brown trout below the wis dells damn a few years ago. I have heard of people catching trout in Lake Mendota and Monona like previously said.
There are some catch and release spring ponds in the Southern Kettle Moraine. Last year when I was there I saw a mid 30's northern swimming around half dead looking. The spring is right there and not very easy for a fish like that to get up there. I think someone released it in there.... Maybe this doesn't count because I didn't catch it???