| | Lake Nacimiento, CA | Lake Isabella, CA | United States |
| Population | 3,050 | 3,553 | 329,725,481 |
| Female Population | 52.4% | 50.3% | 50.5% |
| Male Population | 47.6% | 49.7% | 49.5% |
| Median Age | 40.4 | 36.4 | 38.4 |
| space3 | | | |
| Population - 2010 | 2,408 | 3,287 | 309,327,143 |
| Population - 2000 | 2,176 | 3,315 | 285,036,114 |
| Population - 1990 | 1,556 | 3,323 | 251,960,433 |
| Pop. 2000 to Now | 29.9% | 33.0% | 15.6% |
| Pop. 1990 to Now | 81.7% | 32.7% | 30.8% |
| space4 | | | |
| Population Density | 294.7 | 163.6 | 93.4 |
| Land Area | 10.4 | 21.7 | 3,531,905.4 |
| Water Area | 0.0 | 0.4 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Lake Nacimiento, CA | Lake Isabella, CA | United States |
| Age 0 to 4 | 7.4% | 5.8% | 5.9% |
| Age 5 to 9 | 8.5% | 2.1% | 6.1% |
| Age 10 to 14 | 4.7% | 21.3% | 6.6% |
| Age 15 to 17 | 0.3% | 4.9% | 3.9% |
| Age 18 to 20 | 1.2% | 3.4% | 4.0% |
| Age 21 to 24 | 2.5% | 0.2% | 5.2% |
| Age 25 to 34 | 13.1% | 10.0% | 13.8% |
| Age 35 to 44 | 13.9% | 9.9% | 12.9% |
| Age 45 to 54 | 11.0% | 13.2% | 12.6% |
| Age 55 to 59 | 10.1% | 6.8% | 6.7% |
| Age 60 to 64 | 6.0% | 5.8% | 6.3% |
| Age 65 to 74 | 15.6% | 9.9% | 9.6% |
| Age 75 to 84 | 4.7% | 6.1% | 4.5% |
| Age 85 and over | 1.0% | 0.6% | 1.9% |
| space1 | | | |
| Race | | | |
| | Lake Nacimiento, CA | Lake Isabella, CA | United States |
| White | 76.3% | 67.0% | 59.4% |
| Black | 2.1% | 0.0% | 12.2% |
| Asian | 0.7% | 1.2% | 5.6% |
| Native American | 0.2% | 2.0% | 0.6% |
| Hawaiian, Pacific Islander | 0.3% | 0.0% | 0.2% |
| Other | 3.3% | 0.0% | 0.4% |
| Two or More Races | 3.5% | 8.1% | 3.2% |
| Hispanic | 13.6% | 21.6% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Lake Nacimiento, CA | Lake Isabella, CA | United States |
| Married Population | 64.3% | 37.0% | 49.8% |
| Currently Married | 63.5% | 33.0% | 48.0% |
| Married but Separated | 0.7% | 4.0% | 1.8% |
| Single Population | 35.7% | 63.0% | 50.2% |
| Never Married | 17.4% | 40.9% | 33.8% |
| Divorced | 12.8% | 11.7% | 10.8% |
| Widowed | 5.5% | 10.5% | 5.6% |
| space5 | | | |
| Household Size | 2.40 | 2.50 | 2.60 |
| Households | 1,272 | 1,424 | 124,010,992 |
| Family Households | 806 | 876 | 80,755,759 |
| Married couple, w/children | 33.1% | 7.3% | 30.5% |
| Married couple, no children | 50.6% | 34.2% | 42.9% |
| Non Family Households | 466 | 548 | 43,255,233 |
| Single householder, w/children | 11.3% | 51.1% | 15.8% |
| Single householder, no children | 5.0% | 7.3% | 10.8% |