Hydrogeologic and water quality investigations in the Big Spring Basin, Clayton Co., IA, 1983 water year, G. R. Hallberg, R. D. Libra, E. A. Bettis III, and B. E. Hoyer, 1984, 231 p., 43 figs., 20 tables, 3 appendices. The Open-File Report series consists of interim reports from a variety of ongoing studies, including contract studies with various State and Federal agencies. These reports often have a limited distribution.