We stayed in late June in the Rocky Cove Campground on the lake.  The lake itself is dotted with campgrounds.  Rocky Cove has concrete pad sites, nice and level, both on and away from the lake.  The lake sites have power only, and the Prime sites (opposite the lakeside sites) have water and power both.  We don't have water in our teardrop, so we got water from an unoccupied site.  

The sites are small, and for the summer, don't stay in site #118 (a lakeside site), as it has no protection from the sun.  The sun sets across the lake and although the view is great, the sun bakes the campsite from morning until 9 pm.  The site next door, #120 is nice and shady.  In winter, the desirability of the sites might be reversed.

The odd thing about the campground is that there is no bathroom or showers.  At all.  You have to go to the next campground over, Oak Point.  Not convenient.  Overall, Oak Point appears to be the better choice, with more trees, larger sites and a convenient bathroom (with ice machine at the entrance).  I should note the restroom was "clean enough".  Not terrible, not great.  The shower I used had merely a trickle, but my wife's had great pressure.  The hand dryer in the men's room looked corroded and was out of order (in Oak Point)

All the campgrounds appeared quiet, and the people there were friendly.  We would go back, but stay in Oak Point.

This is a beautiful Park with three separate loops, one for full power and hookups, one with only power and water available and the other with no power. The sides are large and private. Some are wooded and others are open but all were quite nice. Frankly, I'm not sure when I've stayed at a better campground. The bathrooms and showers were spotless and clean three times a day. There's a great playground area for the kids and lots of hiking. Be careful though, there is poison ivy around and ticks can be pretty fierce in Minnesota. We stayed in the East loop and really liked it.