| | St. Clair, MO | Odessa, TX | United States |
| Population | 4,770 | 112,640 | 329,725,481 |
| Female Population | 48.9% | 49.8% | 50.5% |
| Male Population | 51.1% | 50.2% | 49.5% |
| Median Age | 38.9 | 30.7 | 38.4 |
| space3 | | | |
| Population - 2010 | 4,724 | 99,814 | 309,327,143 |
| Population - 2000 | 4,390 | 90,943 | 285,036,114 |
| Population - 1990 | 3,917 | 89,699 | 251,960,433 |
| Pop. 2000 to Now | 6.8% | 37.9% | 15.6% |
| Pop. 1990 to Now | 19.7% | 39.8% | 30.8% |
| space4 | | | |
| Population Density | 1,000.4 | 2,490.8 | 93.4 |
| Land Area | 4.8 | 45.2 | 3,531,905.4 |
| Water Area | 0.0 | 0.3 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | St. Clair, MO | Odessa, TX | United States |
| Age 0 to 4 | 6.2% | 8.9% | 5.9% |
| Age 5 to 9 | 10.0% | 8.6% | 6.1% |
| Age 10 to 14 | 4.1% | 7.5% | 6.6% |
| Age 15 to 17 | 2.1% | 4.7% | 3.9% |
| Age 18 to 20 | 4.6% | 3.9% | 4.0% |
| Age 21 to 24 | 1.8% | 6.2% | 5.2% |
| Age 25 to 34 | 16.5% | 17.4% | 13.8% |
| Age 35 to 44 | 8.6% | 13.5% | 12.9% |
| Age 45 to 54 | 13.4% | 10.4% | 12.6% |
| Age 55 to 59 | 9.1% | 4.9% | 6.7% |
| Age 60 to 64 | 7.4% | 4.4% | 6.3% |
| Age 65 to 74 | 8.7% | 5.9% | 9.6% |
| Age 75 to 84 | 4.1% | 2.6% | 4.5% |
| Age 85 and over | 3.4% | 1.3% | 1.9% |
| space1 | | | |
| Race | | | |
| | St. Clair, MO | Odessa, TX | United States |
| White | 94.1% | 30.1% | 59.4% |
| Black | 0.9% | 6.1% | 12.2% |
| Asian | 0.4% | 1.7% | 5.6% |
| Native American | 1.8% | 0.3% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 0.1% | 0.4% |
| Two or More Races | 2.4% | 1.0% | 3.2% |
| Hispanic | 0.5% | 60.7% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | St. Clair, MO | Odessa, TX | United States |
| Married Population | 49.8% | 50.2% | 49.8% |
| Currently Married | 48.2% | 48.2% | 48.0% |
| Married but Separated | 1.6% | 1.9% | 1.8% |
| Single Population | 50.3% | 49.8% | 50.2% |
| Never Married | 27.6% | 33.8% | 33.8% |
| Divorced | 12.1% | 11.0% | 10.8% |
| Widowed | 10.5% | 5.0% | 5.6% |
| space5 | | | |
| Household Size | 2.28 | 2.60 | 2.60 |
| Households | 2,056 | 42,685 | 124,010,992 |
| Family Households | 1,075 | 28,582 | 80,755,759 |
| Married couple, w/children | 32.3% | 34.7% | 30.5% |
| Married couple, no children | 47.0% | 30.3% | 42.9% |
| Non Family Households | 981 | 14,103 | 43,255,233 |
| Single householder, w/children | 9.2% | 24.5% | 15.8% |
| Single householder, no children | 11.5% | 10.5% | 10.8% |