Through a statistical analysis comparing the Middle Tennessee district with the older Tri-State and Upper Mississippi Valley districts, we evaluate the exploration effort by drilling for zinc in central Tennessee and southern Kentucky. All of the ore deposits are of the Mississippi Valley type and are similar geologically. Through statistical analyses we attempt to answer these questions: If the drilling density in the Middle Tennessee district had been applied to the Tri-State district, how much of the ore in that district would have been found? If this drilling had been done in the Upper Mississippi Valley district, how much of the ore in that district would have been discovered? Which of these two older districts does Middle Tennessee more closely resemble in intensity of zinc mineralization? Is more drilling warranted in the Middle Tennessee district?Our data base includes tonnage and area distributions of ore deposits in the Tri-State district, sizes of orebodies, and probabilities of their recognition in the three districts, and data for the Elmwood mine in the Middle Tennessee district.Our statistical analyses consider the consequences of drilling holes in the three districts at random locations and on square grids at coarse, intermediate, and fine spacings.