Just South of Kentucky, Tennessee Has North America’s Largest Sinkhole

When you're in most of Kentucky, you're never very far away from a cave. In fact, depending on where you are, there could be one beneath the very ground you're currently sitting or standing on.

And because of the Commonwealth's cave systems, sinkholes are hardly uncommon sights. With that in mind, you might think that we Kentuckians could claim the continent's largest sinkhole. You'd be wrong, but you also wouldn't be very far away from your target.

The Largest Sinkhole in North America

Interestingly, anybody can drive through North America's largest sinkhole and never realize where they are. You'd pass an active general store, a Methodist church and its cemetery, and lots of pasture land. It's really one of the most beautiful spots in Tennessee, and it's less than 100 miles from the Kentucky state line.

Grassy Cove, Tennessee, is the unincorporated community that that general store, that Methodist church, and a few residents call home. It's a breathtaking valley that looks like it could have been created digitally by Hollywood visual effects teams, except it's the real thing.

When Did Grassy Cove Form?

To understand the process, you need to know that this area in Tennessee is "karst region," and that means that dissolving bedrock lies beneath the Grassy Cove landscape. When that bedrock dissolves, sinkholes, sinking streams, and caves form.

Grassy Cove has been a long work in progress; it formed around 250 million years ago. And since it is a sinkhole, it will continue "working."

You may ask, "Where does the rainwater go in this valley?" It goes the way all water in sinkholes goes; it goes down. All water coming into Grassy Cove flows to its northern end and then disappears into a cave. A couple of days later, it re-emerges 900 feet lower than Grassy Cove and goes about its business.