| | Moorpark, CA | Duchesne, UT | United States |
| Population | 36,201 | 1,997 | 329,725,481 |
| Female Population | 49.6% | 46.8% | 50.5% |
| Male Population | 50.4% | 53.2% | 49.5% |
| Median Age | 38.8 | 30.6 | 38.4 |
| space3 | | | |
| Population - 2010 | 34,668 | 1,724 | 309,327,143 |
| Population - 2000 | 31,415 | 1,408 | 285,036,114 |
| Population - 1990 | 25,494 | 1,308 | 251,960,433 |
| Pop. 2000 to Now | 15.2% | 22.5% | 15.6% |
| Pop. 1990 to Now | 42.0% | 31.9% | 30.8% |
| space4 | | | |
| Population Density | 2,877.7 | 712.5 | 93.4 |
| Land Area | 12.6 | 2.8 | 3,531,905.4 |
| Water Area | 0.2 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Moorpark, CA | Duchesne, UT | United States |
| Age 0 to 4 | 6.2% | 9.0% | 5.9% |
| Age 5 to 9 | 6.6% | 9.9% | 6.1% |
| Age 10 to 14 | 6.5% | 8.2% | 6.6% |
| Age 15 to 17 | 4.0% | 7.5% | 3.9% |
| Age 18 to 20 | 3.7% | 4.1% | 4.0% |
| Age 21 to 24 | 4.8% | 4.8% | 5.2% |
| Age 25 to 34 | 13.5% | 9.9% | 13.8% |
| Age 35 to 44 | 11.6% | 16.4% | 12.9% |
| Age 45 to 54 | 14.0% | 12.0% | 12.6% |
| Age 55 to 59 | 8.4% | 4.0% | 6.7% |
| Age 60 to 64 | 6.7% | 4.9% | 6.3% |
| Age 65 to 74 | 9.6% | 3.8% | 9.6% |
| Age 75 to 84 | 2.7% | 4.3% | 4.5% |
| Age 85 and over | 1.7% | 1.3% | 1.9% |
| space1 | | | |
| Race | | | |
| | Moorpark, CA | Duchesne, UT | United States |
| White | 52.5% | 91.9% | 59.4% |
| Black | 3.1% | 0.5% | 12.2% |
| Asian | 7.0% | 0.0% | 5.6% |
| Native American | 0.1% | 0.4% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.7% | 0.2% |
| Other | 0.1% | 0.0% | 0.4% |
| Two or More Races | 4.9% | 0.8% | 3.2% |
| Hispanic | 32.2% | 5.7% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Moorpark, CA | Duchesne, UT | United States |
| Married Population | 59.5% | 52.5% | 49.8% |
| Currently Married | 59.0% | 49.7% | 48.0% |
| Married but Separated | 0.5% | 2.8% | 1.8% |
| Single Population | 40.5% | 47.5% | 50.2% |
| Never Married | 30.3% | 33.3% | 33.8% |
| Divorced | 6.4% | 9.3% | 10.8% |
| Widowed | 3.8% | 4.9% | 5.6% |
| space5 | | | |
| Household Size | 3.15 | 3.24 | 2.60 |
| Households | 11,494 | 565 | 124,010,992 |
| Family Households | 9,161 | 451 | 80,755,759 |
| Married couple, w/children | 38.7% | 42.4% | 30.5% |
| Married couple, no children | 47.3% | 31.9% | 42.9% |
| Non Family Households | 2,333 | 114 | 43,255,233 |
| Single householder, w/children | 7.7% | 18.0% | 15.8% |
| Single householder, no children | 6.2% | 7.8% | 10.8% |