I stayed at Elk Rock State Park with my son and his Boy Scout troop. The weather was perfect that night and we were able to have a nice fire. The next day we broke down our tents pretty quickly because of the rain.
We obviously stayed in the group campsite, but the campground is big with lots of trees and good facilities. It even has an equestrian part of the campground for you horse lovers.
Lake Red Rock is really close so it is a great place to stay the night and then pull your boat down to the lake for some fun on the water. Iowa doesn't have any mountains but it makes up for it with a lot of green scenery and some wonderful activities like horseback riding and boating for the family.
This is a very good state park and campground.