Frequently Asked Questions about Devils Millhopper Geological State Park

Question: How deep is the Devil’s Millhopper?
Answer: The sinkhole is about 120 feet deep.

Question: How wide is the Devil’s Millhopper?
Answer: At the top, the sinkhole is 500 feet across from rim to rim.

Question: When did the Devil’s Millhopper form?
Answer: Geologists estimate that the Devil’s Millhopper collapsed approximately 10,000 to 14,000 years ago.

Question: How many steps are there going down into the Devil’s Millhopper?
Answer: There are 236 steps.

Question: How large is the park?
Answer: The park covers an area of 63 acres.

Question: What is the name of the creek flowing into the Devil’s Millhopper?
Answer: The creek is named Deer Run.

Question: Where does the creek go after flowing into the Devil’s Millhopper?
Answer: It flows into fissures in the limerock in the bottom of the sinkhole. The water eventually finds its way back into the aquifer.

Question: Why doesn’t the water flowing in from the creek and the sides of the Devil’s Millhopper fill it up?
Answer: The fissures, or cracks in the limerock at the bottom are large enough to handle the volume of water flowing into the sinkhole. Occasionally, a heavy rainfall will briefly cause a pool to form at the bottom; however, this usually only lasts for a few hours.

Question: How deep has this pool ever been?
Answer: In February 1998, during a heavy rain event, there was a pool of water that was formed approximately 35 feet deep. It took about a week to drain down.