A long-term project to map and catalog all precontact Native American burial mounds in Iowa provides information about the number, location, form, survivorship, and rate of loss of mounds. This analysis reveals previously undocumented mound manifestations, including a large cluster of 200 linear mounds along the central Des Moines River valley. Historical records reveal that at least 7,762 mounds were identified at 1,551 sites in Iowa between 1840 and the present. About 47% of the mounds from these sites can be possibly seen in lidar, with 33% of the total clearly seen in lidar. Data show that mound loss over time is linear. Extrapolation of data suggests that at least 15,000–17,000 mounds stood in Iowa in the nineteenth century, but the actual number was likely higher.
