| | Blunt, SD | Agar, SD | United States |
| Population | 332 | 95 | 329,725,481 |
| Female Population | 44.9% | 43.2% | 50.5% |
| Male Population | 55.1% | 56.8% | 49.5% |
| Median Age | 30.6 | 62.1 | 38.4 |
| space3 | | | |
| Population - 2010 | 355 | 75 | 309,327,143 |
| Population - 2000 | 370 | 82 | 285,036,114 |
| Population - 1990 | 342 | 82 | 251,960,433 |
| Pop. 2000 to Now | -4.9% | -2.4% | 15.6% |
| Pop. 1990 to Now | 2.9% | -2.4% | 30.8% |
| space4 | | | |
| Population Density | 681.7 | 463.4 | 93.4 |
| Land Area | 0.5 | 0.2 | 3,531,905.4 |
| Water Area | 0.0 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Blunt, SD | Agar, SD | United States |
| Age 0 to 4 | 14.8% | 0.0% | 5.9% |
| Age 5 to 9 | 11.4% | 1.1% | 6.1% |
| Age 10 to 14 | 9.3% | 0.0% | 6.6% |
| Age 15 to 17 | 1.2% | 0.0% | 3.9% |
| Age 18 to 20 | 0.0% | 0.0% | 4.0% |
| Age 21 to 24 | 2.1% | 0.0% | 5.2% |
| Age 25 to 34 | 21.7% | 22.1% | 13.8% |
| Age 35 to 44 | 6.6% | 12.6% | 12.9% |
| Age 45 to 54 | 6.9% | 3.2% | 12.6% |
| Age 55 to 59 | 7.2% | 10.5% | 6.7% |
| Age 60 to 64 | 7.2% | 8.4% | 6.3% |
| Age 65 to 74 | 8.7% | 38.9% | 9.6% |
| Age 75 to 84 | 2.7% | 1.1% | 4.5% |
| Age 85 and over | 0.0% | 2.1% | 1.9% |
| space1 | | | |
| Race | | | |
| | Blunt, SD | Agar, SD | United States |
| White | 84.0% | 100.0% | 59.4% |
| Black | 0.0% | 0.0% | 12.2% |
| Asian | 0.0% | 0.0% | 5.6% |
| Native American | 9.6% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 0.0% | 0.4% |
| Two or More Races | 0.6% | 0.0% | 3.2% |
| Hispanic | 5.7% | 0.0% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Blunt, SD | Agar, SD | United States |
| Married Population | 58.9% | 40.4% | 49.8% |
| Currently Married | 58.9% | 40.4% | 48.0% |
| Married but Separated | 0.0% | 0.0% | 1.8% |
| Single Population | 41.1% | 59.6% | 50.2% |
| Never Married | 29.0% | 27.7% | 33.8% |
| Divorced | 8.9% | 21.3% | 10.8% |
| Widowed | 3.3% | 10.6% | 5.6% |
| space5 | | | |
| Household Size | 2.55 | 1.42 | 2.60 |
| Households | 130 | 67 | 124,010,992 |
| Family Households | 88 | 20 | 80,755,759 |
| Married couple, w/children | 29.5% | 10.0% | 30.5% |
| Married couple, no children | 34.1% | 90.0% | 42.9% |
| Non Family Households | 42 | 47 | 43,255,233 |
| Single householder, w/children | 34.1% | 0.0% | 15.8% |
| Single householder, no children | 2.3% | 0.0% | 10.8% |