Lake Huron's Manitoulin Island is the largest lake island in the world. It's so large, in fact, that it has 108 lakes of its own. Three of Manitoulin's largest lakes -- Lake Manitou, Lake Kagawong and Lake Mindemoya -- even have islands of their own, some of which have ponds of their own.

Pockmarked, picturesque Manitoulin is also home to an enduring archaeological mystery. In 1951, Thomas Edward Lee, an archaeologist for the National Museum of Canada, discovered an incredible array of artifacts on a rocky hill near the island's northeastern shore. The site was dubbed Sheguiandah, after the small village nearby.

Four years of excavations would eventually unearth rudimentary scrapers, drills, hammerstones, and projectile points, apparently constructed out of the quarried bedrock jutting from the hill. Blades were in particular abundance. Many thousands of all shapes and sizes were found, some preserved in the cool, forest soils, others drowned in peat bogs, and even more littering the open ground. Documenting the expedition in 1954, Lee imagined prehistoric "quarrying operations of staggering proportions." Clearly, Sheguiandah was a hub of industry.

“It would not be surprising that people who carried out the enormous amount of work done here should also have lived on the site," Lee wrote.

But while Lee and his colleagues uncovered a great many blades and other objects, they didn't turn up a single human bone. Signs of human activity were etched, scraped, and smashed in stone (quartzite to be specific), but there were no human remains. The men and women that worked the quarry at Sheguiandah may have originated from more permanent settlements somewhere else. If that's the case, those settlements have yet to be unearthed.

It is partly due to the lack of remains that dating Sheguiandah has proven extremely difficult. When Lee concluded his excavations in the 1950s, he created quite a buzz by insisting that some of the artifacts were found in deposits dating back to the Ice Age, as many as 30,000 years ago! Suddenly, Manitoulin Island may have been home to the oldest traces of humankind in North America!

The story Lee wove was fascinating. As summarized by his son:

"Early peoples lived and left their stone tools on the Sheguiandah hilltop in a warm period before the last major glacial advance. The returning glaciers caught up and moved those tools - but only a few yards or tens of yards. The tools stayed locked up under the ice for tens of thousands of years, until it melted away. Then a succession of Paleo-Indian and Archaic groups migrated along the north shore of a subarctic Great Lake. Each stopped briefly at Sheguiandah, leaving a scattering of spearpoints and other stone tools on top of the glacial till deposits. About 5000 years ago, the lake basin filled again, temporarily turning the hill into an island in Great Lakes Nipissing. A tremendous stone-quarrying industry sprang up, covering parts of the site at least five feet deep in broken rock."

But the archaeological community generally disagreed. Lee's timeline challenged popular theories insisting that humans didn't reach the heart of North America until after the Laurentide Ice Sheet receded from what is now the northern United States. This glacial retreat heralded the end of the Ice Age roughly 20,000 years ago. Soon, major journals refused to publish Lee's controversial papers on Sheguiandah, and as the discussion faded from public forums, the site itself was slowly forgotten. As Lee's son Robert noted in 2005, "In 1987 neutral observers characterized it as 'Canada's most neglected major site of the past 30 years.'"

In 1991, archaeologists Patrick Julig of Laurentian University and Peter Storck of the Royal Ontario Museum in Toronto led new expeditions to Sheguiandah, and, armed with advances in dating techniques, re-evaluated Lee's claims. They determined that the site was roughly 10,500-years-old, instead envisioning Paleo-Indians as the site's first and only inhabitants after the conclusion of the Ice Age. At the time, Manitoulin Island was almost certainly connected to what is now mainland Ontario, and the inhabitants likely traded their stone tools far and wide.

Manitoulin Island is today a quiet place, home to roughly 12,600 permanent residents who adore the island's untrammeled wilderness and timeless, glacier-worn topography. The controversy surrounding Sheguiandah has settled down. Now, tourists can take guided walks through the site and still find scores of artifacts strewn across the landscape. We may never know who they once belonged to.

(Images: NASA, Thomas E. Lee, American Antiquity, Jhapk)