Based on the historical population data provided for the ZIP code 21644 in Barclay, Maryland, the area has consistently maintained a very low population density over the past decade. The population density has ranged from a low of 33.69 people per square mile in 2022 to a high of 40.09 people per square mile in 2015. As of 2022, the population density stands at 33.69 people per square mile, with a total population of 158 individuals.

Given these population density figures, the ZIP code area can be classified as a remote rural area. Remote rural areas are characterized by very sparse populations, minimal infrastructure, and limited services. The lifestyle in such areas is predominantly agricultural or undeveloped, with a focus on privacy and self-sustainability. Residents in remote rural areas often engage in outdoor and recreational activities, taking advantage of the natural environment.

The estimated number of housing units corresponding to the 2022 population, based on the national average household size of 2.61, is approximately 60 units. This low number of housing units is consistent with the typical land use in remote rural areas, where households often occupy large expanses of land, sometimes more than 5 acres per household.