This place was fantastic. The rates are dirt cheap, but the park is worth many times more. I came in without a reservation and found a huge pull-through campsite on the hill, with a clear view of the lake (it is indeed blue). There was a deep and broad terrace for picnic table and tent, and some pines for shade. It was a little windy when I visited, but not uncomfortably so. It was dark and quiet at night, and I slept well.
The bathroom nearest my campsite was a vault toilet, but a clean one. Real bathrooms are available at the visitor center, a long walk north of my tent.
I recommend following the trail at the north end of the campground for a nice view of the dam (it was a 10 to 15 minute hike for me, narrow but level). The lake is also open for boating and fishing, with a launch ramp near the campground.
The only downside I can think of was the trash I found at my campsite, mostly bottle caps. I spent a few minutes picking it up before I left.