Law Dog- I heard your "lake" was quite the later season mallard honey hole when it was a slough. I never hunted it but people from here used to drive out there in the 1970s and probably the early '80s or whenever it filled up.
People from here used to drive a lot to "the River" to hunt Canadians before the state agency started to reintroduce the "Giants" on the east side counties. I suspect few people drive out to the River to hunt geese anymore.
I only did it a few times but the most memorable one was the time a friend of mine took me to a little piece of state bluff land in Sully County and we pass shot them. I had never had the experience of geese being below me coming up the hill but with a 30 mph tail wind pushing them. That was a wild day.
Yes it was a cattail swamp 40 years ago knee deep lots of rat huts but it was closed to trapping to help control the muskrats. The water was not visible just miles of cattails so thick the “ lake “ caught fire a few times from lighting strikes. It’s considered a fast cycling lake, after the water came up the lake became toxic from all of the dead vegetation floating in it. Killed thousands of different waterfowl.
It had some serious flooding about 10 years ago that increased the depth greatly and cleaned up the bad water, it’s now planted with perch and walleye. Wife talked to a guy in Mitchell she asked if he was one of the guys out fishing on the lake he said no but he’s heard about it.