Roger Van Surksum, 64, of Alexandria said he reeled in the first bone June 14 and he soon teamed with divers Wayne Wagner, 56, of Brandon and Wesley Torgrimson, 49, of Evansville to search the bottom of the lake July 9, the Alexandria Echo Press reported Friday.
The team initially found 10 bones in the area where Van Surksum was fishing in June and discovered hundreds more during additional dives July 17 and Aug. 20.
Van Surksum said he took some of the bones to St. Cloud State University July 17 and researchers determined they were bison bones that could be 200 to 10,000 years old.
"I am having a lot of fun with it and I am going to turn it all over to the state of Minnesota," Van Surksum said. "Who knows? We might have a kill site with artifacts."