Harrison has been assigned the ZIP code 57344.
There were 26 households out of which 11.5% had children under the age of 18 living with them, 69.2% were married couples living together, and 30.8% were non-families. 30.8% of all households were made up of individuals and 23.1% had someone living alone who was 65 years of age or older. The average household size was 1.96 and the average family size was 2.39.
In the CDP the population was spread out with 11.8% under the age of 18, 2.0% from 18 to 24, 15.7% from 25 to 44, 21.6% from 45 to 64, and 49.0% who were 65 years of age or older. The median age was 62 years. For every 100 females there were 82.1 males. For every 100 females age 18 and over, there were 80.0 males.
The median income for a household in the CDP was $25,500, and the median income for a family was $27,250. Males had a median income of $26,875 versus $11,875 for females. The per capita income for the CDP was $13,170. There were 13.0% of families and 14.8% of the population living below the poverty line, including 36.4% of under eighteens and none of those over 64.