Devil's Millhopper, a World Below
Near Gainesville, Florida
About three miles northwest of the University of Florida campus, the earth simply drops away. Devil's Millhopper is a sinkhole one hundred twenty feet deep and five hundred feet wide, a funnel-shaped void in the Florida limestone that has been swallowing visitors' imaginations since at least the eighteen eighties.
The mechanics of its formation are the mechanics of almost all of Florida. Beneath this state, limestone bedrock dissolves slowly in acidic groundwater, creating underground voids over millions of years. When the roof of such a void finally collapses, a sinkhole forms at the surface. This one formed roughly ten thousand years ago.
What makes Devil's Millhopper extraordinary is its depth. Descending the roughly one hundred thirty two wooden steps to the bottom, you pass through more than a hundred feet of exposed rock strata, layer after layer of geological time, including dolostone and phosphatic sands deposited during the Miocene Epoch, between five and twenty-three million years ago. The Ocala Limestone at the deepest visible layers formed in a warm shallow sea more than thirty-four million years ago, when Florida was under water. You walk down through time as much as through space.
At the bottom, a miniature rainforest waits for you. Twelve small streams trickle down the walls, creating a microclimate cool and humid enough to support ferns, mosses, and plant communities that belong in the mountains of the Appalachians rather than the Florida flatwoods. Fossils of marine organisms are visible in the stream banks. Shark teeth have been found here.
The name comes from its resemblance to the hopper of an old grain mill, where material fed in at the top and vanished. Early locals who found animal bones at the bottom decided the mill's owner must be the devil.
The site became a Florida state park in nineteen seventy-four, recognized as a geological landmark with no rival in the state.
