THE geographer's interest in modern descriptive and analytical statistical methods is growing, especially with respect to their potential usefulness in regional analysis. Correlation techniques, including multiple correlation and regression, are particularly suited to aiding the geographer in his traditional study of the areal variations of related phenomena, since the variables always exist in complex interconnection.2 One may properly employ these statistical-cartographic techniques after he has established tentative descriptive hypotheses regarding the mutuality that may exist among the distributions of an area, inferred through the study of individual maps and other sorts of data. Coefficients of correlation and related indices provide general quantitative statements of the degree to which each hypothesis is valid. These may be sharpened through the use of partial correlation techniques which statistically hold constant designated variables while investigating any two. Regression mapping portrays the areal distribution of the degree of correspondence, shows the locations of departures from the average relationship, and provides a basis for formulating additional hypotheses. In this paper attention is focused on the areal variations in the density of the 1950 rural farm population in the Great Plains. Several distinct phenomena are believed to vary in a reciprocal fashion with rural farm population density; these interrelationships are examined, and statements are made about