39 (41). For the five year period 1936-40 livestock sources were responsible for 78.7 percent of all farm cash income in South Dakota, exclusive of government payments. Of all the cash income from livestock sources the sales of the following species of animals accounted for specified percentages: Cattle, 32.7; hogs, 25.5; and sheep, 5.5 (See Figs. I and 2). The distribution of livestock in the state and the boundaries of the areas into which the state was divided for this study is shown by Figs. 3, 4 and 5. Cattle are distributed much more uniformly over the state, with the greatest concentration in the southeastern areas, 1 and 6 (See Fig. 3). Hog production has its greatest concentration in the southeast in Area 1 ( See Fig. 4). Sheep are...