We saw an article about "Dutch Days" in nearby Fulton on www.OnlyInYourState.com, (first weekend in May) and thought it looked like fun. The nearest campground at Thomson causeway recreational area was closed both for repairs and for flooding so this was our best choice.
It was not crowded this early in the season, though most of the sites are pretty private and that wasn't an issue. We stayed in the 60's loop which is more open than most since it has the playground. There's only one shower building, which is clean and well-kept, and it is on the 80's loop, though there are paths to it from the others.
There are a few pull-through sites, but I'm not sure they're indicated. The ADA sites are large and well paved, though the tables do not have wheelchair overhangs.
Fire rings are hit and miss, our site had a low square pit with a non-adjustable flip-over grill, other sites had taller, circular rings, check site photos.
There are two trails downhill to the lake from the 60's loop, no lakeside campsites.
The lake is small but pleasant and stocked with fish. There are boat rentals available and a small restaurant and general store.
We went on day trips to Fulton and Clinton, IA. Eagle point park has a good view of the Mississippi, but  more spectacular views are at Mississippi Palisades State Park, a 50 min drive.
If you don't feel like cooking, a great choice is the Candlelight Inn(s), half an hour to the east or west in Clinton, Sterling or Rock Falls. A great family restaurant/ steakhouse famous for it's "Chicken George" (they'll give you a free sample to get you hooked)