| | Coulee City, WA | Davenport, WA | United States |
| Population | 516 | 1,785 | 329,725,481 |
| Female Population | 40.7% | 51.7% | 50.5% |
| Male Population | 59.3% | 48.4% | 49.5% |
| Median Age | 49.4 | 38.4 | 38.4 |
| space3 | | | |
| Population - 2010 | 562 | 1,736 | 309,327,143 |
| Population - 2000 | 600 | 1,730 | 285,036,114 |
| Population - 1990 | 568 | 1,502 | 251,960,433 |
| Pop. 2000 to Now | -6.7% | 1.5% | 15.6% |
| Pop. 1990 to Now | -1.4% | 16.9% | 30.8% |
| space4 | | | |
| Population Density | 566.4 | 1,071.4 | 93.4 |
| Land Area | 0.9 | 1.7 | 3,531,905.4 |
| Water Area | 0.0 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Coulee City, WA | Davenport, WA | United States |
| Age 0 to 4 | 9.1% | 8.0% | 5.9% |
| Age 5 to 9 | 8.3% | 5.3% | 6.1% |
| Age 10 to 14 | 4.1% | 6.7% | 6.6% |
| Age 15 to 17 | 0.0% | 4.2% | 3.9% |
| Age 18 to 20 | 1.2% | 7.2% | 4.0% |
| Age 21 to 24 | 4.3% | 6.0% | 5.2% |
| Age 25 to 34 | 11.2% | 8.1% | 13.8% |
| Age 35 to 44 | 11.2% | 12.6% | 12.9% |
| Age 45 to 54 | 4.8% | 12.6% | 12.6% |
| Age 55 to 59 | 10.7% | 4.0% | 6.7% |
| Age 60 to 64 | 1.4% | 4.7% | 6.3% |
| Age 65 to 74 | 20.2% | 15.0% | 9.6% |
| Age 75 to 84 | 11.6% | 3.9% | 4.5% |
| Age 85 and over | 1.9% | 1.7% | 1.9% |
| space1 | | | |
| Race | | | |
| | Coulee City, WA | Davenport, WA | United States |
| White | 90.5% | 86.9% | 59.4% |
| Black | 6.2% | 0.1% | 12.2% |
| Asian | 0.0% | 2.0% | 5.6% |
| Native American | 0.0% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.3% | 0.2% |
| Other | 0.0% | 0.0% | 0.4% |
| Two or More Races | 3.3% | 3.4% | 3.2% |
| Hispanic | 0.0% | 7.2% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Coulee City, WA | Davenport, WA | United States |
| Married Population | 64.9% | 61.4% | 49.8% |
| Currently Married | 58.5% | 60.4% | 48.0% |
| Married but Separated | 6.4% | 1.1% | 1.8% |
| Single Population | 35.1% | 38.6% | 50.2% |
| Never Married | 9.6% | 21.3% | 33.8% |
| Divorced | 10.6% | 10.4% | 10.8% |
| Widowed | 14.8% | 6.9% | 5.6% |
| space5 | | | |
| Household Size | 2.14 | 2.55 | 2.60 |
| Households | 241 | 686 | 124,010,992 |
| Family Households | 161 | 478 | 80,755,759 |
| Married couple, w/children | 27.3% | 40.2% | 30.5% |
| Married couple, no children | 41.0% | 47.7% | 42.9% |
| Non Family Households | 80 | 208 | 43,255,233 |
| Single householder, w/children | 11.8% | 7.5% | 15.8% |
| Single householder, no children | 19.9% | 4.6% | 10.8% |