Yes, believe it or not, Iowa was actually tropical in the Tertiary-era, over 3 million years ago.
Also, Iowa was completely under water for millions of years. Dinosaur remains are found in Iowa as well as on every other continent because they were joined in a mega continent called Pangea. Those are just a few of the interesting historical geological facts about Iowa that the students in 4B learned from Cari Nicely, the Henry County Naturalist. They also learned about the 4 glaciers which drastically changed the landscape of Iowa by creating lakes, flat lands, the Loess Hills. Students played a game where they identified fossil remains of creatures from the different periods. Who knows, maybe you could find a Mammoth bone in your own backyard like a family in Oskaloosa did.