Nice natural park along the Mississippi
Lovely old forests and amazing views of the big river, great trails (easy to moderate), wildlife. We were here many years ago and it is quite memorable. It has that Civilian Conservation Corps charm but with modern amenities. Waterfall trail is also worth the hike, nice geology.
Yay: lots of history, great views even without going too far from your car
Nay: very close campsites, none along the lake but all are close to trails. Bugs!
Surprise: exceptional birding! Bring your binoculars. Get up early for the sunrise. Also, this is not in Colorado (where the more famous PIke's Peak is!).