Are these mounds the oldest human-made structures in the Americas?

Two mounds on the Louisiana State University campus may be the oldest known structures in the Americas, with their oldest layers being 11,000 years old. Stratigraphic analysis and carbon dating of ash layers suggest that the mounds were built and used, at least intermittently, over thousands of years. As Prof. Brooks Ellwood notes: “There’s nothing known that is man-made and this old still in existence today in the Americas, except the mounds.” Dr. Jonathan Tomkin, the Associate Director of SESE, was part of a team of authors that published their findings in the American Journal of Science. To read the full report, go to https://www.ajsonline.org/content/322/6/795.