Copyright license: Creative Commons CC BY-SA 4.0. You are free to share, copy, distribute, remix, and adapt the work for any purpose. You must attribute the work in this manner: "Photo by William Whittaker, Office of the State Archaeologist, University of Iowa" For any reuse or distribution, you must make clear to others the license terms of this work and link to the copyright license site: http://creativecommons.org/licenses/by-sa/4.0/
