One extremely persistent rumor in alternative archaeological circles is that there is evidence--suppressed evidence--that the Native American mounds of Wisconsin, Minnesota, and Iowa were built by Vikings. To support this premise, oddly shaped glacial erratics are thought to be "Viking mooring stones," various "rune stones" of very dubious origin are cited, and, as in the case of this story, there are rumors of horse skeletons which were found in mounds--and the evidence suppressed. One of the funniest stories associated with these Viking legends has to do with the Spencer Lake Mound in extreme northwest Wisconsin. There was, undeniably, a horse skull found in Spencer Lake Mound. How it got there is a tale worth telling.
Spencer Lake Mound and the Clam River Focus
The Spencer Lake Mound is a large round, hemispherical burial mound, the largest of several mounds located on terraces near the shore of Spencer Lake, Burnett County, Wisconsin. During the 1935 and 1936 excavations by the University of Wisconsin at Milwaukee, excavators found a total of 58 separate secondary burials, accounting for a total of at least 182 individuals. Artifacts recovered from the site included triangular arrow points, a shaft straightener, red ochre, a hearth, and a few sherds of Clam River pottery, which is part of the BlackDuck ceramic group. Birchbark baskets and the claws and skin of a beaver were recovered from the burials.
The Clam River Focus was established by archaeologist Will McKern, and besides Spencer Lake Mound includes the Clam Lake Mound Group. The people who built and used these mounds to bury their dead lived during the end of the Middle Woodland period, ca 500-700 AD, well before the historic period--and, for those trans-oceanic Viking aficionados, a good 300-500 years before the Viking colony in Newfoundland called L'Anse aux Meadows site was occupied.
How the Story Began
During the summers of 1935 and 1936, the University of Wisconsin excavated Spencer Lake Mound. The principal investigators were Ralph Linton and W. C. McKern; their staff of students included A.C. Spaulding, George Quimby, David Stout, and Joffre Coe--all destined to become pretty famous archaeologists in their own rights. It was in the fall of 1936, probably, when a young college student signed up for a beginning anthropology course taught by Ralph Linton. The young man, who is known in this story only as Mr. P., had been an avid artifact hunter while growing up in northwestern Wisconsin. Conversing with his classmates in 1936, Mr. P. discovered that excavations at the Spencer Lake Mound the previous summer had revealed an astonishing artifact: a horse's skull buried deep within the mound.
Mr. P's Confession
This was quite a shock to Mr. P. After gathering all of his available courage, he went into Linton's office and confessed that in 1928, the then-teen aged Mr. P. and a buddy had spent an afternoon pot-hunting the Spencer Lake Mound.
The boys dug a sizeable hole, consuming the better part of a hot afternoon, without encountering any kind of a recognizable feature. They were about to backfill the opening when one of them suggested that they bury a horse's skull that lay along the edge of a nearby field a short distance away. This seemed like a brilliant suggestion to the undisciplined minds of the boys, so the skull was retrieved and carefully laid in an oriented position at the bottom of the excavation before backfilling commenced. Anticipation of the probable results of this piece of mischief somehow eased the monotony of the backfilling, and the miscreants mutually agreed that in about two hundred years some archaeologist would dig up the skull and conclude that he had found something really worthwhile [from Mr. P., Wisconsin Archeologist 45(2):120 (1964)].