Interstate Technical Group on Abandoned Underground Mines
Fourth Biennial Abandoned Underground Mine Workshop
Abstract: Abandoned Underground Coal Mines in Iowa
Mary R. Howes
Iowa Department of Natural Resources
Geological Survey Bureau
Iowa City, IA
The Geological Survey Bureau compiled coal mine-related data from a variety of sources to develop a database of abandoned underground coal mines in Iowa. The database created from this information that includes tabular and geographic information system components. Information sources included surveyed mine maps prepared while the mines were in operation, maps and reports prepared by the State Mines Inspectors Office, Iowa Geological Survey Annual Reports, and other sources. Coal resource-related geologic data was also compiled by GSB and is now used to help ascertain mining depths and coal thicknesses.
As the data was compiled efforts were made to preserve the original mine maps that included cleaning and enclosing the maps in mylar envelopes. At the same time large-format photographs were taken of the maps. The photographs were used to develop the GIS components of the database and are now used in place of the original maps for most inquiries about the details of mine layout.
Over three thousand mine sites have been located using historic records. Approximately 2,740 are underground mines and 340 are surface mines. The mined extent is known for about 830 underground mines. Approximate extents are known for an additional 370 underground mine sites. About half of the sites are documented as point locations only with varying locational accuracy. Other types of information compiled from the coal mining records include mine entrance types, shaft locations and depths, dates of operation, and superintendent's name. About 270 additional mines for which no location data is available may have operated in Iowa and were compiled as a list of names and post office box addresses.
Thirty-two Iowa counties had some coal mining activity between 1840 and 1994, although most mining was concentrated in about ten counties. All coal mined in Iowa was from Pennsylvanian-age rocks. Within the Pennsylvanian, the lower Cherokee Group was the primary source of coal, although significant amounts of stratigraphically higher coal were mined in the area around Centerville, Iowa.