The composition of the family has changed drastically over the last 40 years. In 1970, married couples constituted 72% of the total families and by 2010, married couples had declined to just 50% of families.
As the proportion of married couples has decreased, the total number of single-person or non-family households has increased (from 20% to 34% of all families). Single-parent families also grew over the period.
In 2010, married-couple families constituted 58% of the households in rural areas of Thurston County – a proportion significantly higher than several of the urban areas (especially Olympia, Tumwater, Bucoda, Tenino) and the Chehalis Reservation. Not all urban areas, however, had lower proportions of married families; both Rainier and Yelm had over 50% of their households headed by a married couple in 2010.