Rock Lake (Tyranena) is a feature in southern Wisconsin that is probably best known for its many underwater structures, some of which are pyramidal in shape. Some suggest that they were built by the indigenous Aztalan people. Frank Joseph has written two books about the lake, Atlantis in Wisconsin and The Lost Pyramids of Rock Lake . He maintains that the anomalies are burial mounds of people who worked the huge copper mines of Michigan from 3000 BC until around 1200 BC. He further claims that “the mines were excavated and operated by engineers from Atlantis.”[104.239] Native American traditions describe these people as pale-skinned, with hair like fire!
Even more exotic are claims that the lake can produce “energy disturbances” that has caused equipment to malfunction(a) as well as high energy frequencies that effects human consciousness!(b). For good measure a serpent monster has also been claimed for the lake(c).
The Rock Lake Research Society was founded in 1998 and included experts with the objective of documenting and preserving the archaeology of the lake. Their work has continued ever since. One of the founding members, the late Archie Eschborn, has written The Dragon in the Lake , which encapsulates the research and theories regarding Rock Lake.
Atlantis in Wisconsin: New Revelations About the Lost Sunken City,  is one of Frank Joseph‘s earliest books in which he conjured up highly speculative links between Atlantis and the geology, archaeology and mythology of Wisconsin. He returned to the Atlantis Wisconsin theme a few years later with the publication of The Lost Pyramids of Rock Lake. Joseph promotes the idea that the copper mines of Michigan were used to fuel the European Bronze Age, an idea promoted by others, including most recently by Gavin Menzies, who suggests that the Minoans exploited the Michigan mines. Menzies had already written about the Chinese ‘discovering’ America decades before Columbus, but seems reluctant to attribute to the Chinese of an earlier age the ability to also have reached America, but is content to accept that the Minoans did!