Examining census data on each of 3,100 U.S. counties for 1950, 1960, and 1970, the amount of net migration was analyzed in terms of general urban to rural migration, migration and Standard Metropolitan Statistical Area (SMSA) adjacency, 26 rural county subregions, and the kinds of county characteristics associated with population change. Results indicated: rural county growth of more than 4% between April 1970 and July 1973 as compared with an urban growth rate of 3%; a net rural migration of more than 1,000,000 between 1970-73; a steady decline of urban migrants over the 23-year period; an increase in the rate of net migration to SMSAs with fewer than 250,000 people between 1970-73; a higher rate of inmigration among the 629 rural counties not adjacent to a SMSA than among any metropolitan category; population growth among all 26 subregions between 1970-73; a reversal among the 7 subregions which had had declining populations during the 60's; a higher growth rate among rural counties with State colleges; a consistent association between the migration of older people for recreation/retirement purposes and total population growth and net migration in both adjacent and nonadjacent counties; growth among southern counties with less than 5% black population; recent growth among counties with an agricultural workforce; and no correlation between recent rural growth and rural areas already dependent upon manufacturing. (JC)