The topography of Drummond Island is unreal and visually spectacular. From Maxton Plains to Big Shoal Beach, from Marblehead to the Dolomite quarry - it's landforms weave a rich tapestry of geological history not found anywhere else in the world. Quite a feat for an island comprised of only 83,000 acres.
Drummond Island is part of what is known as the Niagara Escarpment… a geologic formation that surrounds 4 of the 5 Great Lakes, and which is chiefly responsible for Niagara Falls being the glory that it is.
It is this geological history that links Drummond Island to the Mighty Mac.
In the late ‘twenties, T. L. Durocher, of DeTour opened the present Drummond Island Quarry to obtain rock for the construction and rip-rapping of docks and breakwaters on the Great Lakes. Mr. Durocher, a marine contractor, realized that the blocky nature of Engadine dolomite made it ideal for this purpose. Within a few years, several hundred thousand tons of it were quarried and transported for the repair and construction of marine installations at Frankfort, Mackinaw City, South Chicago, and other Great Lakes points.
By 1949 Drummond Dolomite was a 24 –hour per day operation and they shipped out 2,275,000 tons that year.
Drummond Island Dolomite Quarry, Drummond Island MI circa 1940's
Then in 1954 construction of the Mackinac Bridge began. One of the first steps was to sink the large, double-walled cylinders that form the bases of the two main tower piers. These cylinders are called caissons (cay-säns). Sunk down into the bedrock on the lake floor - the caissons presented a great challenge for the divers involved in their fabrication.
The building of the Mackinac Bridge caissons
These huge caissons were to form the foundation of the bridge - no small task. That is why the bridge engineers turned to the quarry on Drummond Island. Dolomite from the quarry at Drummond was used to fill these massive caissons. The dolomite, along with huge amounts of grout, provided the base for the bridge towers.
Loading lake frieghters at Drummond Island with dolomite bound for the bridge construction site
Dolomite from Drummond Island was shipped in self-unloading lake frieghters to the bridge site. These vessels carried 12,000 tons per load.
The vessel "John A Kling" unloads dolomite from Drummond into a bridge caisson
At the completion of the bridge construction a plaque honoring Drummond Island, Michigan with providing the stone for the Bridge Authority Office buildings and the aggregate for the bridge foundations was placed on the Mackinac Bridge.
It is not the first or last time Drummond Island dolomite played an important role in the building of this nation's infrustructure.
"Let it be such work that our descendents will thank us -- that men will say as they look upon the labor and raw substance: SEE THIS, our fathers did for us."
-John Ruskin (1819-1900), writer as quoted by Dr. David B. Steinman Mackinac Bridge Designer