Ohio. Glacial Grooves of Lake Erie’s Kelleys Island
North of Ohio’s Marblehead Peninsula is an island with strange channels cut deeply into limestone rock. Extending for more than a hundred meters, the rounded indentations are smooth and parallel to each other. We know today that the grooves were formed 18,000 years ago by a massive continental ice sheet that came southward from present-day Canada. Grinding across existing layers of rock, the glacier obliterated nearly everything in its path. For several years I used photographs of the grooves in a course I taught. Mentioning the site to my wife as we were driving through northern Ohio, we decided to make a detour to see the grooves.
Glacial Grooves State Park is on tiny Kelleys Island (11.4 km2), located in the southwestern part of Lake Erie. First occupied by Native Americans, the island fell under the British who called it Sandusky Island. During the War of 1812, the island was used as a meeting point by forces under U.S. General William Henry Harrison. Six families lived on the island in 1830 when the first limestone quarry was established. A few years months later bothers Datus and Irad Kelley began purchasing land and by 1833, they owned all of what they named Kelleys Island. Docks were soon added for shipping limestone, fruit, and lumber. Eventually Kelley Islands Lime and Transport (1886-1960) became the world’s largest producer of lime and limestone. The island was also a focus of agricultural production. Wine grapes were first grown there in the early 1840s and by the early twentieth century, 1.8 million liters of wine were being exported each year.
Today the island is a vacation destination with campgrounds, beaches, summer homes, restaurants, and a marina. Several farms continue to operate on the island along with a small limestone quarry. Although the island’s permanent population is just three hundred, seasonal tourism brings more than 250,000 visitors each year. There is a small airport, but most tourists travel there by ferry or private boat.
Arriving in Marblehead, we purchased tickets for the thirty-minute (5.5 kilometer) ferry ride to the island. The ferry can accommodate cars, motorhomes, and even large trucks. Visitors who bring their cars or motorhomes can drive a section of State Route 575 that runs through the center of the island. After lunch at a restaurant near the marina, we rented a golfcart for the short drive on SR 575 (aka Division Street) to Kelleys Island State Park. The park is located near the northern shore and close to East Quarry which operated between 1933 and 1940. Columbus limestone quarried there was formed 350 to 450 million years ago during the Devonian Period and at a time when present-day Ohio was located south of the Equator and covered by an inland sea. Evidence of the area’s marine past can be seen in the fossilized remains of brachiopods, cephalopods, corals, and other organisms. Parking our golfcart, we walked to a trail and footbridge that had been built for better views of the long glacial striations. The grooves were created during the Pleistocene when the massive Laurentide Icesheet pushed southward from its origin near Hudson Bay, Canada. The slow-moving continental glacier incorporated bits of rock, soil, and other debris as it cut and reshaped the park’s limestone rock.
Fifty years ago, the grooves would not have been visible to tourists since it was common for miners to pile rock waste into the shallow depression where the grooves are located. In 1972 the debris was removed, revealing the largest and most accessible glacial grooves in the world. The grooves are 122 meters long, eleven meters wide, and 4.5 meters deep. For geologists, their north-south orientation offers clues about the direction and movement of the Laurentide Icesheet.
We continued west on Titus Road to West Lakeshore Drive and around the island’s perimeter. Providing access to summer homes, Lakeshore Drive encircles the western and southern edge of the island’s rocky shoreline. Returning to the island’s more populated southern coast, we dropped off our golfcart and walked back towards the ferry terminal. Along the way we passed a pyramid-shaped roof constructed over “Inscription Rock” where Native Americans left drawings.
