| | Eufaula, OK | Eureka, KS | United States |
| Population | 2,731 | 2,295 | 329,725,481 |
| Female Population | 56.2% | 51.0% | 50.5% |
| Male Population | 43.8% | 49.0% | 49.5% |
| Median Age | 49.3 | 44.2 | 38.4 |
| space3 | | | |
| Population - 2010 | 2,808 | 2,637 | 309,327,143 |
| Population - 2000 | 2,639 | 2,914 | 285,036,114 |
| Population - 1990 | 2,652 | 2,974 | 251,960,433 |
| Pop. 2000 to Now | 7.5% | -21.0% | 15.6% |
| Pop. 1990 to Now | 7.0% | -22.6% | 30.8% |
| space4 | | | |
| Population Density | 414.7 | 1,002.2 | 93.4 |
| Land Area | 6.6 | 2.3 | 3,531,905.4 |
| Water Area | 3.0 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Eufaula, OK | Eureka, KS | United States |
| Age 0 to 4 | 1.7% | 6.2% | 5.9% |
| Age 5 to 9 | 7.3% | 9.2% | 6.1% |
| Age 10 to 14 | 5.5% | 5.0% | 6.6% |
| Age 15 to 17 | 3.7% | 2.9% | 3.9% |
| Age 18 to 20 | 3.7% | 0.0% | 4.0% |
| Age 21 to 24 | 1.4% | 4.0% | 5.2% |
| Age 25 to 34 | 8.1% | 11.3% | 13.8% |
| Age 35 to 44 | 13.5% | 13.6% | 12.9% |
| Age 45 to 54 | 11.4% | 10.3% | 12.6% |
| Age 55 to 59 | 7.9% | 7.2% | 6.7% |
| Age 60 to 64 | 5.8% | 6.4% | 6.3% |
| Age 65 to 74 | 18.7% | 13.6% | 9.6% |
| Age 75 to 84 | 6.5% | 5.1% | 4.5% |
| Age 85 and over | 4.7% | 5.1% | 1.9% |
| space1 | | | |
| Race | | | |
| | Eufaula, OK | Eureka, KS | United States |
| White | 70.9% | 89.2% | 59.4% |
| Black | 2.0% | 0.9% | 12.2% |
| Asian | 0.6% | 0.5% | 5.6% |
| Native American | 17.2% | 0.1% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 0.0% | 0.4% |
| Two or More Races | 9.0% | 3.9% | 3.2% |
| Hispanic | 0.3% | 5.4% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Eufaula, OK | Eureka, KS | United States |
| Married Population | 30.6% | 48.0% | 49.8% |
| Currently Married | 28.2% | 43.4% | 48.0% |
| Married but Separated | 2.4% | 4.6% | 1.8% |
| Single Population | 69.4% | 52.0% | 50.2% |
| Never Married | 28.1% | 25.9% | 33.8% |
| Divorced | 26.9% | 16.6% | 10.8% |
| Widowed | 14.4% | 9.5% | 5.6% |
| space5 | | | |
| Household Size | 2.29 | 2.35 | 2.60 |
| Households | 1,102 | 946 | 124,010,992 |
| Family Households | 591 | 601 | 80,755,759 |
| Married couple, w/children | 13.9% | 21.0% | 30.5% |
| Married couple, no children | 30.3% | 37.1% | 42.9% |
| Non Family Households | 511 | 345 | 43,255,233 |
| Single householder, w/children | 21.7% | 32.6% | 15.8% |
| Single householder, no children | 34.2% | 9.3% | 10.8% |