Alley Spring State Park, Mo. 2004

Alley Spring has an average daily flow of 81 million gallons and holds the record for the largest credible measured flow of any Ozark spring (2750 cfs or 1.776 billion gallons of water, on April 22, 1974). In 1893, George McCaskill built the present mill with a steel turbine as power source.
See 2005 pictures here.