Try the Mississippi river. In Pool 2 it's all catch and release, though. I've caught walleyes while shore-fishing in downtown St. Paul. I like to use nightcrawlers, fished on or just above the bottom. You'll catch lots of other stuff, too, including carp and cats 20+ lbs. Lots of sheepheads, too. Fishing can be fast and furious from shore or a dock on the river.
If you're looking for something larger than panfish from shore, the river's the place to go.