REDISCOVERING THE ANDERSON MILLS MASTODON: A 19TH CENTURY FIND FROM GRANT COUNTY, WISCONSIN

In July of 1897 numerous mastodon (Mammut americanum) bones were discovered near the town of Boaz, Wisconsin. Another partial mastodon skeleton was unearthed roughly 50 kilometers to the southwest in the small hamlet of Anderson Mills the following summer, in July of 1898. This find was better preserved and produced more than sixty complete elements. Shortly after being recovered, the remains from both localities were purchased separately by the State of Wisconsin for the University of Wisconsin Geology Museum (UWGM).

In the fall of 1915 a mastodon skeleton was put on display in the UWGM which for almost a century was attributed to the Boaz mastodon. Many lines of evidence indicate, however, that this skeleton is a composite. Most of the bones are from the Anderson Mills mastodon, while the others are assigned tentatively to the Boaz mastodon.

The left femur, mandible, and several other bones from the mounted skeleton appear in historical photographs of the Anderson Mills site. Newspaper accounts of this find also mention two ribs with healed fractures, both of which are present. The left humerus and left femur ­­­from the Anderson Mills mastodon yielded AMS radiocarbon dates of 12,910 ± 140 cal BP (11,040 ± 50 ¹⁴C yr BP) and 12,910 ± 150 cal BP (11,050 ± 60 ¹⁴C yr BP), respectively. The right tibia and left first rib differ greatly from the other bones in preservation, wear, and coloration. They have AMS radiocarbon dates of 12,010 ± 180 cal BP (10,280 ± 45 ¹⁴C yr BP) and 12,220 ± 190 cal BP (10,370 ± 45 ¹⁴C yr BP), respectively, and are most likely from the Boaz mastodon.