| | Inchelium, WA | Pendleton, OR | United States |
| Population | 347 | 16,861 | 329,725,481 |
| Female Population | 50.1% | 45.6% | 50.5% |
| Male Population | 49.9% | 54.4% | 49.5% |
| Median Age | 35.7 | 36.9 | 38.4 |
| space3 | | | |
| Population - 2010 | 436 | 16,656 | 309,327,143 |
| Population - 2000 | 389 | 16,354 | 285,036,114 |
| Population - 1990 | 393 | 15,126 | 251,960,433 |
| Pop. 2000 to Now | 9.5% | 1.5% | 15.6% |
| Pop. 1990 to Now | 8.4% | 9.7% | 30.8% |
| space4 | | | |
| Population Density | 13.1 | 1,438.3 | 93.4 |
| Land Area | 26.4 | 11.7 | 3,531,905.4 |
| Water Area | 0.0 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Inchelium, WA | Pendleton, OR | United States |
| Age 0 to 4 | 2.6% | 7.5% | 5.9% |
| Age 5 to 9 | 7.8% | 6.1% | 6.1% |
| Age 10 to 14 | 9.2% | 7.0% | 6.6% |
| Age 15 to 17 | 11.5% | 4.1% | 3.9% |
| Age 18 to 20 | 4.0% | 4.5% | 4.0% |
| Age 21 to 24 | 2.9% | 3.7% | 5.2% |
| Age 25 to 34 | 8.4% | 14.1% | 13.8% |
| Age 35 to 44 | 19.0% | 14.0% | 12.9% |
| Age 45 to 54 | 11.0% | 11.0% | 12.6% |
| Age 55 to 59 | 6.3% | 5.8% | 6.7% |
| Age 60 to 64 | 4.3% | 5.5% | 6.3% |
| Age 65 to 74 | 10.7% | 10.4% | 9.6% |
| Age 75 to 84 | 2.0% | 3.6% | 4.5% |
| Age 85 and over | 0.3% | 2.6% | 1.9% |
| space1 | | | |
| Race | | | |
| | Inchelium, WA | Pendleton, OR | United States |
| White | 7.2% | 78.4% | 59.4% |
| Black | 0.0% | 1.9% | 12.2% |
| Asian | 0.0% | 0.6% | 5.6% |
| Native American | 74.4% | 2.1% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.1% | 0.2% |
| Other | 0.0% | 0.7% | 0.4% |
| Two or More Races | 18.4% | 4.2% | 3.2% |
| Hispanic | 0.0% | 12.0% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Inchelium, WA | Pendleton, OR | United States |
| Married Population | 42.3% | 44.8% | 49.8% |
| Currently Married | 40.1% | 42.3% | 48.0% |
| Married but Separated | 2.2% | 2.6% | 1.8% |
| Single Population | 57.7% | 55.2% | 50.2% |
| Never Married | 43.0% | 33.7% | 33.8% |
| Divorced | 11.8% | 14.8% | 10.8% |
| Widowed | 2.9% | 6.7% | 5.6% |
| space5 | | | |
| Household Size | 2.88 | 2.57 | 2.60 |
| Households | 120 | 5,876 | 124,010,992 |
| Family Households | 79 | 3,555 | 80,755,759 |
| Married couple, w/children | 53.2% | 32.9% | 30.5% |
| Married couple, no children | 13.9% | 37.1% | 42.9% |
| Non Family Households | 41 | 2,321 | 43,255,233 |
| Single householder, w/children | 30.4% | 22.4% | 15.8% |
| Single householder, no children | 2.5% | 7.6% | 10.8% |