There is a walk in NWI called a Death March. Its located in the Indiana Dunes. Its a warm water discharge perfect for winter fishing. In the summer its called boaters island or party island. This place in the summer looks like a Girls Gone Wild video shoot. But to get there by land its a 2.8 mile hike up and down dunes.
Here is a quick video 500x faster and some shots
Before the March tried some winter pin fishing but finding flowing water was hard to come by. Most was frozen.