Kenneth S. Johnson is associate director of the Oklahoma Geological Survey (OGS) and visiting professor@the University of Oklahoma (OU). He has a B.S. and M.S. in geology, and a B.S. in geological engineering, all from OU; he holds a Ph.D. in geology from the University of Illinois. His research and publications cover a wide range of environmental and mineral-resource issues, with special emphasis in recent years on evaporite rocks and karst processes. His contributions to this article are approved by the director of the OGS.