This late stage Folsom preform was discovered in the Lake Ilo National
Wildlife Refuge sometime between 1991 and 1992. It was found on the
lakebed by the Lake Ilo Archaeological Project team after the water was
lowered in 1989 to allow replacement of the aging dam. Thirty-seven site
locations were studied within the 600-acre area of exposed land. More
than 58,000 stone artifacts were collected. This site is located in
western North Dakota near the town of Dunn Center.