- Geological Survey (U.S.)22
- Iowa. Department of Natural Resources. Geological Survey Bureau3
- Barr, G. L.1
- Clark, Allen K., cartographer1
- Geological Survey (U.S.), cartographer, issuing body1
- Keefer, Donald A. (Donald Allen), 1963-1
- Lewis, Barney D.1
- Margat, Jean F.1
- Pickett, Thomas E.1
- Tucker, Robert D.1
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