UTAH: Potato starch residues found on 10,900-year-old stone grinding tools from the North Creek Shelter site may be the oldest known evidence of potato domestication and consumption in North America. The granules belong to a species known as the Four Corners potato, which is native to the southwestern United States, although rare today. In Utah’s Escalante Valley, they are found exclusively around archaeological sites, suggesting these tubers were an important part of prehistoric human diets in the area. —Jason Urbanus