Based primarily on 1980 census data, the bulletin presents five sets of tables which describe changes in population which have occurred in South Dakota as a result of migration into and out of the state. Table 1 provides state of origin/destination, rank, number, and percentage data on migration into and out of South Dakota from 1975-80. Figures indicate 69,514 persons moved to the state and 90,019 moved out of the state during this period, with Minnesota being the leading state of both origin and destination. Table 2 shows the age, number, and rate of net migration for South Dakota from 1960-70 and 1970-80. For both decades, statistics indicate that the highest rate of migration occurred among 25-29 year-olds leaving the state. Table 3 contains net migration figures for South Dakota by age and sex for 1970-80. Table 4 presents numbers and rates of population change by county from 1970-80, revealing that 13 of 66 counties experienced increases in population ranging from 1.7% to 23.7%, while the remaining 53 counties witnessed population decreases ranging from 1.5% to 28.5%. Table 5 enumerates numbers and rates of net migration by age group and sex for each South Dakota county from 1970-80. (NEC)