| | Buffalo, WV | Marion, OH | United States |
| Population | 979 | 36,053 | 329,725,481 |
| Female Population | 51.5% | 44.2% | 50.5% |
| Male Population | 48.5% | 55.8% | 49.5% |
| Median Age | 47 | 36.9 | 38.4 |
| space3 | | | |
| Population - 2010 | 1,240 | 36,795 | 309,327,143 |
| Population - 2000 | 1,171 | 35,318 | 285,036,114 |
| Population - 1990 | 969 | 34,075 | 251,960,433 |
| Pop. 2000 to Now | 7.9% | 0.6% | 15.6% |
| Pop. 1990 to Now | 30.3% | 4.2% | 30.8% |
| space4 | | | |
| Population Density | 699.3 | 3,059.0 | 93.4 |
| Land Area | 1.4 | 11.8 | 3,531,905.4 |
| Water Area | 0.2 | 0.1 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Buffalo, WV | Marion, OH | United States |
| Age 0 to 4 | 3.8% | 6.0% | 5.9% |
| Age 5 to 9 | 5.7% | 5.3% | 6.1% |
| Age 10 to 14 | 5.4% | 6.1% | 6.6% |
| Age 15 to 17 | 4.9% | 3.0% | 3.9% |
| Age 18 to 20 | 2.9% | 3.6% | 4.0% |
| Age 21 to 24 | 5.3% | 5.7% | 5.2% |
| Age 25 to 34 | 8.6% | 18.1% | 13.8% |
| Age 35 to 44 | 12.1% | 12.5% | 12.9% |
| Age 45 to 54 | 12.7% | 12.5% | 12.6% |
| Age 55 to 59 | 10.3% | 6.6% | 6.7% |
| Age 60 to 64 | 7.9% | 6.9% | 6.3% |
| Age 65 to 74 | 14.7% | 8.5% | 9.6% |
| Age 75 to 84 | 3.5% | 3.6% | 4.5% |
| Age 85 and over | 2.3% | 1.7% | 1.9% |
| space1 | | | |
| Race | | | |
| | Buffalo, WV | Marion, OH | United States |
| White | 99.6% | 81.2% | 59.4% |
| Black | 0.0% | 8.6% | 12.2% |
| Asian | 0.0% | 0.2% | 5.6% |
| Native American | 0.0% | 0.2% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.1% | 0.2% |
| Other | 0.4% | 0.4% | 0.4% |
| Two or More Races | 0.0% | 5.3% | 3.2% |
| Hispanic | 0.0% | 4.1% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Buffalo, WV | Marion, OH | United States |
| Married Population | 50.3% | 38.9% | 49.8% |
| Currently Married | 49.2% | 35.4% | 48.0% |
| Married but Separated | 1.1% | 3.4% | 1.8% |
| Single Population | 49.7% | 61.1% | 50.2% |
| Never Married | 24.4% | 36.8% | 33.8% |
| Divorced | 17.8% | 17.9% | 10.8% |
| Widowed | 7.6% | 6.5% | 5.6% |
| space5 | | | |
| Household Size | 2.69 | 2.49 | 2.60 |
| Households | 356 | 12,268 | 124,010,992 |
| Family Households | 232 | 7,213 | 80,755,759 |
| Married couple, w/children | 34.5% | 23.2% | 30.5% |
| Married couple, no children | 48.3% | 41.3% | 42.9% |
| Non Family Households | 124 | 5,055 | 43,255,233 |
| Single householder, w/children | 6.5% | 23.5% | 15.8% |
| Single householder, no children | 10.8% | 12.0% | 10.8% |