| | Williston, ND | Walla Walla, WA | United States |
| Population | 27,368 | 33,765 | 329,725,481 |
| Female Population | 45.7% | 47.3% | 50.5% |
| Male Population | 54.3% | 52.7% | 49.5% |
| Median Age | 30.9 | 36.5 | 38.4 |
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| Population - 2010 | 16,081 | 32,522 | 309,327,143 |
| Population - 2000 | 12,512 | 29,686 | 285,036,114 |
| Population - 1990 | 13,131 | 26,478 | 251,960,433 |
| Pop. 2000 to Now | 137.8% | 11.5% | 15.6% |
| Pop. 1990 to Now | 126.6% | 25.0% | 30.8% |
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| Population Density | 1,181.3 | 2,499.1 | 93.4 |
| Land Area | 23.2 | 13.5 | 3,531,905.4 |
| Water Area | 0.1 | 0.0 | 264,836.8 |
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| Est. Total Population By Age | | | |
| | Williston, ND | Walla Walla, WA | United States |
| Age 0 to 4 | 9.4% | 4.2% | 5.9% |
| Age 5 to 9 | 7.7% | 5.7% | 6.1% |
| Age 10 to 14 | 7.9% | 6.4% | 6.6% |
| Age 15 to 17 | 3.7% | 3.7% | 3.9% |
| Age 18 to 20 | 2.6% | 7.7% | 4.0% |
| Age 21 to 24 | 6.1% | 6.1% | 5.2% |
| Age 25 to 34 | 21.1% | 13.6% | 13.8% |
| Age 35 to 44 | 16.4% | 12.8% | 12.9% |
| Age 45 to 54 | 9.3% | 11.7% | 12.6% |
| Age 55 to 59 | 4.5% | 5.5% | 6.7% |
| Age 60 to 64 | 3.5% | 4.7% | 6.3% |
| Age 65 to 74 | 4.5% | 9.3% | 9.6% |
| Age 75 to 84 | 1.2% | 4.7% | 4.5% |
| Age 85 and over | 1.9% | 3.7% | 1.9% |
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| Race | | | |
| | Williston, ND | Walla Walla, WA | United States |
| White | 71.9% | 66.1% | 59.4% |
| Black | 6.6% | 2.4% | 12.2% |
| Asian | 1.5% | 2.2% | 5.6% |
| Native American | 1.8% | 0.4% | 0.6% |
| Hawaiian, Pacific Islander | 0.3% | 0.2% | 0.2% |
| Other | 0.8% | 0.0% | 0.4% |
| Two or More Races | 5.0% | 4.4% | 3.2% |
| Hispanic | 12.0% | 24.2% | 18.4% |
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| Marriage & Family | | | |
| | Williston, ND | Walla Walla, WA | United States |
| Married Population | 49.1% | 42.9% | 49.8% |
| Currently Married | 48.5% | 39.8% | 48.0% |
| Married but Separated | 0.7% | 3.2% | 1.8% |
| Single Population | 50.9% | 57.1% | 50.2% |
| Never Married | 32.5% | 38.3% | 33.8% |
| Divorced | 14.6% | 12.8% | 10.8% |
| Widowed | 3.7% | 6.0% | 5.6% |
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| Household Size | 2.40 | 2.36 | 2.60 |
| Households | 11,216 | 12,583 | 124,010,992 |
| Family Households | 6,376 | 7,151 | 80,755,759 |
| Married couple, w/children | 35.6% | 32.0% | 30.5% |
| Married couple, no children | 38.7% | 41.2% | 42.9% |
| Non Family Households | 4,840 | 5,432 | 43,255,233 |
| Single householder, w/children | 21.8% | 16.8% | 15.8% |
| Single householder, no children | 3.8% | 9.9% | 10.8% |