We enjoyed our weekend at Thomson Causeway with our popup.  We stayed at site 41.  Although I would have liked the pad to be a little longer, it was still a nice site.  Not a lot of privacy, but being right on the water was great.  Definitely need bugspray, but my boys LOVED catching frogs along the rocks.  Bathrooms are a short walk from this site and were clean.  Water pump was also a short walk.  We enjoyed bike riding around the campsite.  There is a longer bike path that will take you to Clinton.  We bought firewood right outside the park for $3 a pallet.  We will definitely add Thomson to our list to return for our next trip.  I made note that I would love to reserve site 60 or 69... great views of the Mississippi... I assume these are the most sought after sites.