Posted in Geology, History, Northwestern Ohio, Park review

Glacial Grooves State Memorial

The glacial grooves on Kelley’s Island are a designated National Natural Landmark. They were formed during the last Ice Age about 18,000 years ago, and they are the world’s largest, known glacial striations. Typically glacial striations are formed when boulders and gravel are dragged across the bedrock under the immense weight of a glacier. Geologists rely on these natural features to determine the direction in which the now-melted ice once flowed. However according to the Ohio Department of Natural Resources, geologists now think that the glacial grooves in Ohio may have been formed by sand-charged water flowing at great speed and pressure through channels at the base of glacier. At the pinnacle of the last ice age, Kelley’s Island was underneath a mile of ice, so the pressure would have been incredible.

A view from the base of the grooves

In their present form, the glacial grooves are about 430 feet in length (131 meters), 15 feet deep (4.6 meters), 35 feet wide (10.7 meters). However the Historical Association of Kelley’s Island explains that the world’s largest example of glacial striations was much longer a couple of centuries ago, extending from its current site the whole way into Lake Erie. The grooves are much shorter now because people quarried this geological wonder for its Columbus limestone which formed when this area was the bed of a shallow sea some 400 million years ago. However after becoming a state memorial park in 1923 the site has been protected from further quarrying. The Glacial Grooves State Memorial is now managed by the Ohio Historical Society because of its important role in Ohio’s natural history.

If you go to Kelley’s Island, besides visiting the glacial grooves there are a number of other attractions including Kelley’s Island State Park (where we camped and swam at its beach) and Inscription Rock. I didn’t know about Inscription Rock when I visited the area, but if I had I certainly would have checked it out. It is a flat rock on which Native Americans carved petroglyphs. Archaeologists believe that the petroglyphs were the work of Algonquian-speaking groups affiliated with the “Fire Nation” confederacy and that they were made about 1643 A.D.

I will close out by including a few more views of the glacial grooves from different angles. It’s definitely worth a visit.

Glacial grooves
Glacial grooves
Glacial grooves
Additional reading


Address: 920 Division Street Kelleys Island, Ohio 43438

Location: Glacial Grooves is located on Kelleys Island, Erie County, in Lake Erie 8 miles north of Sandusky. Ferries depart from Marblehead and Sandusky.

GPS Coordinates: 41.579498,-82.76001

View or get directions from Google Maps.

More on the Lake Erie area

© Deborah Platt, Robert Platt and 2012 to 2021

13 thoughts on “Glacial Grooves State Memorial

    1. Yes, we brought our car. We camped overnight at the state park camp site. Visited the glacial grooves and beach that were adjacent to the camp site. And there are some small trails to a quarry. There’s also an ancient petroglpyph, which we did not see.

    1. Thank you, Carol! I’m not sure how one goes about being discovered, but wouldn’t that be fun? However the fact that some of these places are hard to find out about is one of our inspirations for creating this blog. I can’t believe I went the whole way to Kelley’s Island and didn’t visit Inscription Rock because I had never heard of it.

      So do you live close enough to these places to actually visit any of them, or must you remain content with being an armchair traveler? 🙂

      1. I live in California, so it’ll be armchair traveling for me for a while…at least to Ohio. I kind of hate to admit this, but I’ve never been to Ohio and when I used to think of it, I would think of “farming” or great big flat spaces of land. Your photos have shown me just how little I knew of Ohio! It’s beautiful!!! Not that great big open spaces of farmland aren’t beautiful in themselves, but I just never thought of Ohio in the way that I see it in your photos. Anyway, maybe someone will discover you for a travel magazine or something the same way you were discovered when someone saw that one photo of yours and purchased it. Your photos really should be somewhere where more people can see how beautiful it is to be in Ohio. 🙂

        1. Carol, your preconceptions of Ohio aren’t that far off. At one point the entire state was nearly deforested so that the land could be used for agriculture.However, as farming has become more and more efficient, less land is dedicated to it. So at this point “only” about 55% of Ohio is farmland.

          And you are right about Ohio being flat, too. Although the Appalachian foothills extend into the southeastern portion of Ohio, the vast majority of Ohio has experienced no tectonic uplift. Almost all of the cliffs you see in our blog have resulted from vast quantities of glacial meltwater eroding the bedrock near creeks and rivers.

          It turns out that I used to live in California, too. I got my bachelor’s degree from UCSB. Unfortunately since I was a poor student without a car, I didn’t get to explore my surroundings all that much. 🙁 However I have made a few trips back there as a toursist since then. 🙂

          1. Well…Ohio is beautiful in your photos, so keep them coming. I went to school at UC Berkeley, and I live in Fairfield, which is not far from the Bay Area. I love California because you never need to go far to get to just about anything you want to, beaches, mountains, forests, and on and on…you know. Your photos always look so professional and polished, I really love them, and I’m learning a lot as well…it’s all great. 🙂

          2. Thanks, Carol. Since you live in the Bay Area, I’ll mention that I think Muir Woods is one of the most astonishing and beautiful places on earth.

            As to my photos, since I am looking back over old photos to illustrate blog posts, I can see that I have been gradually improving over time… partly because I’ve learned a thing or two, and partly because I’m using a better camera. However, I think the thing that has been a real plus is that I now do a little photo-editing on almost every photo before posting it. I may play with the white balance, re-compose a photo by cropping it, fiddle with the saturation, sharpen it here or there, etc. Since I am still on the steep part of the learning curve when it comes to photo-editing, I still have a lot to learn. However I think it’s worthwhile because it lets me pretend to be a better photographer than I really am.

    1. Karen, thank you! It’s gratifying to hear that our post inspired your visit. If you post photos or do a write up on Brandywine Falls, let me know and I’ll take a look.

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