The Spencer Lake site was excavated in 1936 by W. C. McKern, Milwaukee Public Museum Curator of Anthropology at that time. The site is an ancient (AD 1100–1400) burial mound located near Spencer Lake in Burnett County in northwest Wisconsin. At the bottom of the mound, an intact horse skull was discovered, a startling find as it was believed that horses had gone extinct in North America around 10-12 thousand years ago and not reintroduced until the arrival of the Spanish. Two students, upon hearing of the discovery, confessed to placing the skull at the bottom of a pit they had dug into the mound, but McKern and his crew were positive that there was no disturbance of the soils around it.
In 2004, a sample was taken from the skull and sent to two different labs for radiocarbon dating. Both lab results confirmed that the Spencer Lake horse skull was modern, and that the horse had most likely lived during the late eighteenth century or early nineteenth century. (110+/-40 BP; Beta-167209, and 190+/-35 BP; Stafford SR-6189).
