The expert says there are "billions of dollars of real estate built over mine shafts" across Iowa. In fact, a segment of the Norwood mine runs under Iowa Highway 141. Norwood is just one of 222 coal mines that Butzke documented as being in operation across the Des Moines area from the 1840s to 1947, and no moratorium has ever been put in place for building on top of them. About 44 percent of the mines, including Norwood and most of the larger mines once in operation across the Des Moines area, have detailed records of where the mine shafts and tunnels are located. According to an Iowa Department of Natural Resources' geological survey, at least 5,500 underground mines have operated in Iowa and cover nearly 15,000 acres.
Excerpted from DesMoinesRegister.com.
