| | Mesquite, NV | Castaic, CA | United States |
| Population | 20,019 | 18,017 | 329,725,481 |
| Female Population | 49.6% | 50.0% | 50.5% |
| Male Population | 50.4% | 50.0% | 49.5% |
| Median Age | 59.7 | 38.2 | 38.4 |
| space3 | | | |
| Population - 2010 | 15,305 | 18,134 | 309,327,143 |
| Population - 2000 | 9,389 | 18,001 | 285,036,114 |
| Population - 1990 | 1,871 | 7,647 | 251,960,433 |
| Pop. 2000 to Now | 117.7% | 5.8% | 15.6% |
| Pop. 1990 to Now | 992.4% | 149.0% | 30.8% |
| space4 | | | |
| Population Density | 633.9 | 2,481.0 | 93.4 |
| Land Area | 31.6 | 7.3 | 3,531,905.4 |
| Water Area | 0.4 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Mesquite, NV | Castaic, CA | United States |
| Age 0 to 4 | 4.1% | 6.5% | 5.9% |
| Age 5 to 9 | 4.2% | 6.5% | 6.1% |
| Age 10 to 14 | 5.0% | 8.1% | 6.6% |
| Age 15 to 17 | 2.6% | 4.5% | 3.9% |
| Age 18 to 20 | 2.1% | 3.0% | 4.0% |
| Age 21 to 24 | 2.2% | 4.2% | 5.2% |
| Age 25 to 34 | 7.4% | 13.4% | 13.8% |
| Age 35 to 44 | 8.6% | 12.5% | 12.9% |
| Age 45 to 54 | 9.4% | 15.2% | 12.6% |
| Age 55 to 59 | 5.0% | 9.2% | 6.7% |
| Age 60 to 64 | 7.4% | 6.1% | 6.3% |
| Age 65 to 74 | 24.9% | 7.5% | 9.6% |
| Age 75 to 84 | 14.0% | 2.5% | 4.5% |
| Age 85 and over | 3.1% | 0.9% | 1.9% |
| space1 | | | |
| Race | | | |
| | Mesquite, NV | Castaic, CA | United States |
| White | 65.2% | 49.0% | 59.4% |
| Black | 1.0% | 1.7% | 12.2% |
| Asian | 2.2% | 11.9% | 5.6% |
| Native American | 0.9% | 0.1% | 0.6% |
| Hawaiian, Pacific Islander | 0.6% | 0.1% | 0.2% |
| Other | 0.1% | 1.1% | 0.4% |
| Two or More Races | 1.7% | 7.3% | 3.2% |
| Hispanic | 28.2% | 28.8% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Mesquite, NV | Castaic, CA | United States |
| Married Population | 61.1% | 59.6% | 49.8% |
| Currently Married | 59.3% | 58.5% | 48.0% |
| Married but Separated | 1.8% | 1.2% | 1.8% |
| Single Population | 38.9% | 40.4% | 50.2% |
| Never Married | 18.9% | 28.3% | 33.8% |
| Divorced | 11.0% | 7.0% | 10.8% |
| Widowed | 9.0% | 5.1% | 5.6% |
| space5 | | | |
| Household Size | 2.34 | 3.19 | 2.60 |
| Households | 8,522 | 5,656 | 124,010,992 |
| Family Households | 5,921 | 4,727 | 80,755,759 |
| Married couple, w/children | 14.8% | 41.3% | 30.5% |
| Married couple, no children | 68.9% | 41.1% | 42.9% |
| Non Family Households | 2,601 | 929 | 43,255,233 |
| Single householder, w/children | 8.7% | 6.5% | 15.8% |
| Single householder, no children | 7.6% | 11.1% | 10.8% |