Explore 400 million years of Michigan in the making! Your journey begins in the Devonian Period when Michigan was covered by a saltwater sea and massive fish hunted for food along large coral reefs. Ferns and mosses the size of modern-day trees filled the swampy forest during the Paleozoic Era. The sounds of shifting sheets of ice crashing lead visitors into the Ice Age where they will find actual mastodon bones recovered from a farm just north of Muskegon (a life-sized mastodon is on display in Coming to the Lakes).