St. Croix is apparently the largest state park in MN. It is pretty large and spread out. It takes a good 10 minutes to get to the campground after you enter.
And from the campground it takes another 10 minutes to get to the beach area and playground. The playground is an older style wood one. The beach seemed pretty decent with a good sized picnic area. In my opinion the Riverview Campground was terrible. There were little to no trees between sites and there is no view of the river. At some sites the fire rings were no more than 5 feet from your neighbor's fire ring. The walk-in sites were also pretty bad. Site 56 is pretty much right on the parking lot. The rest were only a few feet apart and rather sad to call a walk-in site. Your 'walk-in' site is about a 10 foot walk. Paint Rock Springs wasn't much better. Rather cramped and no privacy from your neighbors. Unfortunate for such a large park. If you like some privacy then Old Logging Trail is the way to go since it has pretty good tree coverage. The best sites are on the outsides of the loops. But the ones on the inside aren't too bad either.