I have not visited this area but I have a coworker that goes there often. In fact he will be at Wigwam next weekend. Those campgrounds as well as most in the area are really geared toward the fishermen and their boats. Don't expect any beaches, etc. But if that's your purpose he recommends Wigwam since it's right at the mouth of the Rainy River as it joins Lake of the Woods. It's 1 of 2 places on Lake of the Woods he returns to yearly.
He also mentioned Zippel Bay State Park which is close and has a beach but they do not have hookups.
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