The Office of Migrant Services' (OMS) summary presents demographic data on the 2,500 migrant families in 25 housing centers in 14 California counties in 1980. The typical migrant family in an OMS center is shown to be a Mexican family of 4, with 2 parents between the ages of 18 and 44, who have completed 2 to 6 years of school, and have 2 to 3 children and possibly a grandparent or other relative living with the family. For five months, three members of the household work in the field, and two of the children attend day or infant care within the center or summer school, then they return to Mexico to enter their children in school. Tables, accompanied by a brief narrative, cover: migrant center occupancy, family size, age of family members, school years completed by persons over 18, ethnic category of head of household, length of stay, and family home base. Migrant tracking, a new category, provides estimated data on "last work stop by state" and "next work stop by state" (other than home base or vicinity of state migrant center). A list of migrant center addresses, operational dates of OMS centers, and a map showing the location of each center are included. (AH)