09/07/2026
Interesting
🪨 On a Lake Erie island there is a slab of bedrock with grooves carved into it so large and so smooth that people assume they were made by machines.
They were not. The Glacial Grooves on Kelleys Island were cut by an ice sheet somewhere around eighteen thousand years ago, when a glacier a mile or more thick dragged rock and debris across the limestone underneath it like a file. What is left is a channel roughly four hundred feet long and thirty five feet wide, scoured with long parallel flutes that curve away down the length of the stone.
It is considered the largest easily accessible example of glacial grooving in the world. Quarrying in the 1800s destroyed a great deal of what was originally exposed on the island before anyone thought to protect what remained. You can walk the platform around it in ten minutes, and the strange part is how fresh the surface looks, as though the ice pulled through last winter instead of before there were people here.
Have you made it out to the islands, and which one is your favorite?
