| | Oklahoma, PA | Preston Heights, IL | United States |
| Population | 956 | 2,633 | 329,725,481 |
| Female Population | 50.6% | 53.8% | 50.5% |
| Male Population | 49.4% | 46.2% | 49.5% |
| Median Age | 52.2 | 34.5 | 38.4 |
| space3 | | | |
| Population - 2010 | 790 | 2,793 | 309,327,143 |
| Population - 2000 | 915 | 2,527 | 285,036,114 |
| Population - 1990 | 977 | 2,750 | 251,960,433 |
| Pop. 2000 to Now | -19.2% | 12.0% | 15.6% |
| Pop. 1990 to Now | -24.4% | 2.9% | 30.8% |
| space4 | | | |
| Population Density | 1,575.0 | 3,065.2 | 93.4 |
| Land Area | 0.6 | 0.9 | 3,531,905.4 |
| Water Area | 0.0 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Oklahoma, PA | Preston Heights, IL | United States |
| Age 0 to 4 | 3.0% | 6.3% | 5.9% |
| Age 5 to 9 | 5.2% | 5.3% | 6.1% |
| Age 10 to 14 | 3.0% | 11.2% | 6.6% |
| Age 15 to 17 | 2.5% | 3.1% | 3.9% |
| Age 18 to 20 | 2.2% | 4.5% | 4.0% |
| Age 21 to 24 | 5.5% | 4.4% | 5.2% |
| Age 25 to 34 | 17.3% | 15.8% | 13.8% |
| Age 35 to 44 | 4.0% | 11.5% | 12.9% |
| Age 45 to 54 | 10.4% | 12.4% | 12.6% |
| Age 55 to 59 | 9.1% | 5.4% | 6.7% |
| Age 60 to 64 | 15.8% | 4.6% | 6.3% |
| Age 65 to 74 | 14.3% | 10.5% | 9.6% |
| Age 75 to 84 | 6.5% | 4.7% | 4.5% |
| Age 85 and over | 1.2% | 0.3% | 1.9% |
| space1 | | | |
| Race | | | |
| | Oklahoma, PA | Preston Heights, IL | United States |
| White | 91.9% | 22.2% | 59.4% |
| Black | 0.5% | 43.1% | 12.2% |
| Asian | 0.0% | 0.2% | 5.6% |
| Native American | 0.0% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 0.0% | 0.4% |
| Two or More Races | 2.4% | 6.2% | 3.2% |
| Hispanic | 5.1% | 28.3% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Oklahoma, PA | Preston Heights, IL | United States |
| Married Population | 58.1% | 40.0% | 49.8% |
| Currently Married | 56.6% | 38.3% | 48.0% |
| Married but Separated | 1.5% | 1.7% | 1.8% |
| Single Population | 41.9% | 60.0% | 50.2% |
| Never Married | 28.8% | 43.3% | 33.8% |
| Divorced | 5.8% | 10.0% | 10.8% |
| Widowed | 7.3% | 6.7% | 5.6% |
| space5 | | | |
| Household Size | 2.27 | 2.66 | 2.60 |
| Households | 421 | 982 | 124,010,992 |
| Family Households | 290 | 588 | 80,755,759 |
| Married couple, w/children | 17.6% | 24.8% | 30.5% |
| Married couple, no children | 63.1% | 32.5% | 42.9% |
| Non Family Households | 131 | 394 | 43,255,233 |
| Single householder, w/children | 9.0% | 28.4% | 15.8% |
| Single householder, no children | 10.3% | 14.3% | 10.8% |