I live in Monticello and you can ice fish at at the mouth of the Big Monon. You want to fish on the west side of the bridge off the north bank. It is opposite side of the road from Tall Timbers Marina. There is a boat ramp there and a place to park. I believe there is a little trailer office that you have to pay to park. It might cost $5 or so to park. You can catch some fish there but more times than not it is a slow bite. could have just been my luck, you never know. The big monon is a great place to catch a lot of crappie and some nice gills. I used to live on the north end of the big monon and during deer season you can catch all the crappie you can handle right up against the bank at times. I would hunt in the mornings, fish in the early afternoon and head back out hunting. I miss those days!! good luck!