| | Buffalo, SD | Durant, OK | United States |
| Population | 318 | 18,358 | 329,725,481 |
| Female Population | 42.1% | 51.7% | 50.5% |
| Male Population | 57.9% | 48.3% | 49.5% |
| Median Age | 51.3 | 33.9 | 38.4 |
| space3 | | | |
| Population - 2010 | 328 | 15,899 | 309,327,143 |
| Population - 2000 | 380 | 13,549 | 285,036,114 |
| Population - 1990 | 488 | 12,823 | 251,960,433 |
| Pop. 2000 to Now | -1.8% | 41.4% | 15.6% |
| Pop. 1990 to Now | -23.6% | 49.4% | 30.8% |
| space4 | | | |
| Population Density | 574.0 | 687.7 | 93.4 |
| Land Area | 0.6 | 26.7 | 3,531,905.4 |
| Water Area | 0.0 | 0.1 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Buffalo, SD | Durant, OK | United States |
| Age 0 to 4 | 2.8% | 5.3% | 5.9% |
| Age 5 to 9 | 3.5% | 7.2% | 6.1% |
| Age 10 to 14 | 8.2% | 6.0% | 6.6% |
| Age 15 to 17 | 5.7% | 3.1% | 3.9% |
| Age 18 to 20 | 5.3% | 6.3% | 4.0% |
| Age 21 to 24 | 2.5% | 7.6% | 5.2% |
| Age 25 to 34 | 7.5% | 16.7% | 13.8% |
| Age 35 to 44 | 9.1% | 12.4% | 12.9% |
| Age 45 to 54 | 12.0% | 10.2% | 12.6% |
| Age 55 to 59 | 11.3% | 4.5% | 6.7% |
| Age 60 to 64 | 11.0% | 4.8% | 6.3% |
| Age 65 to 74 | 15.7% | 8.5% | 9.6% |
| Age 75 to 84 | 5.0% | 4.6% | 4.5% |
| Age 85 and over | 0.3% | 2.8% | 1.9% |
| space1 | | | |
| Race | | | |
| | Buffalo, SD | Durant, OK | United States |
| White | 95.3% | 64.2% | 59.4% |
| Black | 0.0% | 2.8% | 12.2% |
| Asian | 0.0% | 1.1% | 5.6% |
| Native American | 0.0% | 14.4% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.2% | 0.2% |
| Other | 1.9% | 0.1% | 0.4% |
| Two or More Races | 2.8% | 8.2% | 3.2% |
| Hispanic | 0.0% | 8.9% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Buffalo, SD | Durant, OK | United States |
| Married Population | 55.5% | 41.3% | 49.8% |
| Currently Married | 55.5% | 39.0% | 48.0% |
| Married but Separated | 0.0% | 2.3% | 1.8% |
| Single Population | 44.5% | 58.7% | 50.2% |
| Never Married | 26.8% | 34.9% | 33.8% |
| Divorced | 13.2% | 17.7% | 10.8% |
| Widowed | 4.4% | 6.2% | 5.6% |
| space5 | | | |
| Household Size | 2.04 | 2.42 | 2.60 |
| Households | 156 | 7,268 | 124,010,992 |
| Family Households | 84 | 4,379 | 80,755,759 |
| Married couple, w/children | 19.0% | 24.3% | 30.5% |
| Married couple, no children | 58.3% | 34.8% | 42.9% |
| Non Family Households | 72 | 2,889 | 43,255,233 |
| Single householder, w/children | 19.0% | 24.8% | 15.8% |
| Single householder, no children | 3.6% | 16.2% | 10.8% |