There was more coal mining under the city of Springfield than previously thought.
Some cases of mine subsidence in the south part of Springfield last year led to a discovery that more ground under Springfield had been mined for coal.
Scott Elrick with the State Geological Survey says they found an area between MacArthur and Fifth and between Ash and Laurel that had been mined in the 1800's.
Elrick compares the finding to a new discovery when doing family genealogy.
"It's almost the equivalent of finding a long lost cousin that you had no idea existed and adding him into the family tree," he said.
Elrick is part of a continuing effort to map all of the areas that were mined across the state. Currently he says they have less than half of the maps of all the mines. A map of the known mines can be found at www.isgs.illinois.edu/ilmines.