(CNN) - Most kids end the summer with nothing more than a suntan to show for it. But, four kids in Iowa have something big to show for their vacation.
They found a 20,000-year-old mastodon tooth tucked behind a stretch of trees next to a creek in the northeast region of the state.
Professors say because of the good condition of the tooth, there could be even more remains from the Ice Age animal in this same creek where the tooth was found.
Click the video player above to hear from the kids who made the discovery.