Barnard, South DakotaBarnard is an unincorporated community in Brown County, South Dakota, United States.HistoryBarnard was laid out in 1906, and named for a local resident. A post office was established at Barnard in 1910.DemographicsThe population in Barnard is 36. There are 5 people per square mile. The median age in Barnard is 57.3. The number of people per household in Barnard is 2.1.