| | Hermiston, OR | Gallup, NM | United States |
| Population | 19,141 | 21,901 | 329,725,481 |
| Female Population | 51.1% | 50.2% | 50.5% |
| Male Population | 48.9% | 49.8% | 49.5% |
| Median Age | 30.4 | 34.5 | 38.4 |
| space3 | | | |
| Population - 2010 | 16,753 | 21,795 | 309,327,143 |
| Population - 2000 | 13,154 | 20,209 | 285,036,114 |
| Population - 1990 | 10,040 | 19,154 | 251,960,433 |
| Pop. 2000 to Now | 35.3% | 5.2% | 15.6% |
| Pop. 1990 to Now | 77.2% | 11.0% | 30.8% |
| space4 | | | |
| Population Density | 2,334.3 | 1,095.6 | 93.4 |
| Land Area | 8.2 | 20.0 | 3,531,905.4 |
| Water Area | 0.0 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Hermiston, OR | Gallup, NM | United States |
| Age 0 to 4 | 8.0% | 7.6% | 5.9% |
| Age 5 to 9 | 8.9% | 8.0% | 6.1% |
| Age 10 to 14 | 9.8% | 9.8% | 6.6% |
| Age 15 to 17 | 4.5% | 5.6% | 3.9% |
| Age 18 to 20 | 6.1% | 2.8% | 4.0% |
| Age 21 to 24 | 5.0% | 2.9% | 5.2% |
| Age 25 to 34 | 13.3% | 14.7% | 13.8% |
| Age 35 to 44 | 14.1% | 14.3% | 12.9% |
| Age 45 to 54 | 10.7% | 10.0% | 12.6% |
| Age 55 to 59 | 5.3% | 5.1% | 6.7% |
| Age 60 to 64 | 3.1% | 5.2% | 6.3% |
| Age 65 to 74 | 7.0% | 9.2% | 9.6% |
| Age 75 to 84 | 3.1% | 3.5% | 4.5% |
| Age 85 and over | 1.2% | 1.3% | 1.9% |
| space1 | | | |
| Race | | | |
| | Hermiston, OR | Gallup, NM | United States |
| White | 44.0% | 16.8% | 59.4% |
| Black | 0.8% | 1.4% | 12.2% |
| Asian | 0.4% | 3.4% | 5.6% |
| Native American | 0.4% | 44.4% | 0.6% |
| Hawaiian, Pacific Islander | 0.1% | 0.2% | 0.2% |
| Other | 0.0% | 0.0% | 0.4% |
| Two or More Races | 3.2% | 2.0% | 3.2% |
| Hispanic | 51.1% | 31.7% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Hermiston, OR | Gallup, NM | United States |
| Married Population | 50.0% | 40.7% | 49.8% |
| Currently Married | 48.4% | 37.7% | 48.0% |
| Married but Separated | 1.6% | 3.1% | 1.8% |
| Single Population | 50.0% | 59.3% | 50.2% |
| Never Married | 35.1% | 42.5% | 33.8% |
| Divorced | 10.6% | 12.0% | 10.8% |
| Widowed | 4.4% | 4.7% | 5.6% |
| space5 | | | |
| Household Size | 2.95 | 2.92 | 2.60 |
| Households | 6,423 | 7,313 | 124,010,992 |
| Family Households | 4,567 | 4,896 | 80,755,759 |
| Married couple, w/children | 37.9% | 24.8% | 30.5% |
| Married couple, no children | 29.8% | 31.1% | 42.9% |
| Non Family Households | 1,856 | 2,417 | 43,255,233 |
| Single householder, w/children | 22.3% | 29.4% | 15.8% |
| Single householder, no children | 10.0% | 14.6% | 10.8% |