During World War II, Poston was the site of the Poston War Relocation Center, which was one of the United States' largest Japanese internment camps, where over 17,000 Japanese-Americans were held over a three-year period. The camp sites are now home to a monument dedicated to those who died and suffered while in internment.
There were 101 households out of which 66.3% had children under the age of 18 living with them, 66.3% were married couples living together, 15.8% had a female householder with no husband present, and 8.9% were non-families. 6.9% of all households were made up of individuals and 2.0% had someone living alone who was 65 years of age or older. The average household size was 3.85 and the average family size was 3.92.
In the CDP the population was spread out with 41.9% under the age of 18, 10.8% from 18 to 24, 30.1% from 25 to 44, 13.1% from 45 to 64, and 4.1% who were 65 years of age or older. The median age was 23 years. For every 100 females there were 110.3 males. For every 100 females age 18 and over, there were 107.3 males.
The median income for a household in the CDP was $17,625, and the median income for a family was $17,065. Males had a median income of $15,859 versus $13,125 for females. The per capita income for the CDP was $6,938. About 41.5% of families and 46.3% of the population were below the poverty line, including 54.5% of those under age 18 and 18.2% of those age 65 or over.