Hines and neighboring Burns, the county seat, form a small metropolitan area, which is the largest population center in Harney County.
According to the United States Census Bureau, the city has a total area of 2.4 square miles (6.2 km²), of which, 2.4 square miles (6.1 km²) of it is land and 0.04 square miles (0.1 km²) of it (0.84%) is water.
There were 641 households out of which 31.8% had children under the age of 18 living with them, 63.5% were married couples living together, 6.4% had a female householder with no husband present, and 26.2% were non-families. 21.8% of all households were made up of individuals and 8.7% had someone living alone who was 65 years of age or older. The average household size was 2.50 and the average family size was 2.89.
In the city the population was spread out with 26.6% under the age of 18, 6.3% from 18 to 24, 27.0% from 25 to 44, 26.1% from 45 to 64, and 14.0% who were 65 years of age or older. The median age was 40 years. For every 100 females there were 106.5 males. For every 100 females age 18 and over, there were 98.7 males.
The median income for a household in the city was $40,917, and the median income for a family was $43,452. Males had a median income of $32,772 versus $22,458 for females. The per capita income for the city was $15,783. About 6.6% of families and 9.9% of the population were below the poverty line, including 10.1% of those under age 18 and 17.3% of those age 65 or over.