| | Seneca, OR | Unity, OR | United States |
| Population | 206 | 41 | 329,725,481 |
| Female Population | 51.5% | 41.5% | 50.5% |
| Male Population | 48.5% | 58.5% | 49.5% |
| Median Age | 54.3 | 67.5 | 38.4 |
| space3 | | | |
| Population - 2010 | 200 | 71 | 309,327,143 |
| Population - 2000 | 223 | 131 | 285,036,114 |
| Population - 1990 | 191 | 87 | 251,960,433 |
| Pop. 2000 to Now | 0.9% | -45.8% | 15.6% |
| Pop. 1990 to Now | 17.8% | -18.4% | 30.8% |
| space4 | | | |
| Population Density | 259.1 | 64.1 | 93.4 |
| Land Area | 0.8 | 0.6 | 3,531,905.4 |
| Water Area | 0.0 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Seneca, OR | Unity, OR | United States |
| Age 0 to 4 | 3.9% | 0.0% | 5.9% |
| Age 5 to 9 | 8.7% | 9.8% | 6.1% |
| Age 10 to 14 | 2.4% | 0.0% | 6.6% |
| Age 15 to 17 | 0.0% | 0.0% | 3.9% |
| Age 18 to 20 | 0.0% | 0.0% | 4.0% |
| Age 21 to 24 | 4.9% | 0.0% | 5.2% |
| Age 25 to 34 | 15.0% | 4.9% | 13.8% |
| Age 35 to 44 | 3.4% | 4.9% | 12.9% |
| Age 45 to 54 | 14.6% | 9.8% | 12.6% |
| Age 55 to 59 | 3.4% | 7.3% | 6.7% |
| Age 60 to 64 | 13.1% | 9.8% | 6.3% |
| Age 65 to 74 | 15.0% | 29.3% | 9.6% |
| Age 75 to 84 | 2.9% | 24.4% | 4.5% |
| Age 85 and over | 12.6% | 0.0% | 1.9% |
| space1 | | | |
| Race | | | |
| | Seneca, OR | Unity, OR | United States |
| White | 90.8% | 100.0% | 59.4% |
| Black | 0.0% | 0.0% | 12.2% |
| Asian | 0.0% | 0.0% | 5.6% |
| Native American | 2.4% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 0.0% | 0.4% |
| Two or More Races | 1.0% | 0.0% | 3.2% |
| Hispanic | 5.8% | 0.0% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Seneca, OR | Unity, OR | United States |
| Married Population | 60.6% | 35.1% | 49.8% |
| Currently Married | 55.4% | 35.1% | 48.0% |
| Married but Separated | 5.1% | 0.0% | 1.8% |
| Single Population | 39.4% | 64.9% | 50.2% |
| Never Married | 16.0% | 13.5% | 33.8% |
| Divorced | 16.0% | 35.1% | 10.8% |
| Widowed | 7.4% | 16.2% | 5.6% |
| space5 | | | |
| Household Size | 1.91 | 1.46 | 2.60 |
| Households | 108 | 28 | 124,010,992 |
| Family Households | 55 | 7 | 80,755,759 |
| Married couple, w/children | 18.2% | 0.0% | 30.5% |
| Married couple, no children | 70.9% | 85.7% | 42.9% |
| Non Family Households | 53 | 21 | 43,255,233 |
| Single householder, w/children | 10.9% | 14.3% | 15.8% |
| Single householder, no children | 0.0% | 0.0% | 10.8% |