| | Santa Margarita, CA | Eagle, ID | United States |
| Population | 800 | 29,665 | 329,725,481 |
| Female Population | 59.0% | 51.0% | 50.5% |
| Male Population | 41.0% | 49.0% | 49.5% |
| Median Age | 46 | 45.5 | 38.4 |
| space3 | | | |
| Population - 2010 | 1,431 | 20,012 | 309,327,143 |
| Population - 2000 | 1,123 | 11,085 | 285,036,114 |
| Population - 1990 | 1,154 | 3,327 | 251,960,433 |
| Pop. 2000 to Now | 25.1% | 186.0% | 15.6% |
| Pop. 1990 to Now | 21.8% | 852.8% | 30.8% |
| space4 | | | |
| Population Density | 1,547.4 | 974.5 | 93.4 |
| Land Area | 0.5 | 30.4 | 3,531,905.4 |
| Water Area | 0.0 | 0.5 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Santa Margarita, CA | Eagle, ID | United States |
| Age 0 to 4 | 0.0% | 5.3% | 5.9% |
| Age 5 to 9 | 0.0% | 5.6% | 6.1% |
| Age 10 to 14 | 5.8% | 8.5% | 6.6% |
| Age 15 to 17 | 0.0% | 5.3% | 3.9% |
| Age 18 to 20 | 6.5% | 2.8% | 4.0% |
| Age 21 to 24 | 0.0% | 1.9% | 5.2% |
| Age 25 to 34 | 18.9% | 7.7% | 13.8% |
| Age 35 to 44 | 12.6% | 12.2% | 12.9% |
| Age 45 to 54 | 13.0% | 13.3% | 12.6% |
| Age 55 to 59 | 3.5% | 8.4% | 6.7% |
| Age 60 to 64 | 16.3% | 7.0% | 6.3% |
| Age 65 to 74 | 0.0% | 14.2% | 9.6% |
| Age 75 to 84 | 0.0% | 6.3% | 4.5% |
| Age 85 and over | 23.5% | 1.5% | 1.9% |
| space1 | | | |
| Race | | | |
| | Santa Margarita, CA | Eagle, ID | United States |
| White | 80.5% | 85.6% | 59.4% |
| Black | 0.0% | 0.6% | 12.2% |
| Asian | 0.0% | 1.7% | 5.6% |
| Native American | 0.0% | 0.4% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.4% | 0.2% |
| Other | 0.0% | 0.2% | 0.4% |
| Two or More Races | 6.3% | 3.0% | 3.2% |
| Hispanic | 13.3% | 8.1% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Santa Margarita, CA | Eagle, ID | United States |
| Married Population | 35.8% | 67.2% | 49.8% |
| Currently Married | 35.8% | 67.0% | 48.0% |
| Married but Separated | 0.0% | 0.1% | 1.8% |
| Single Population | 64.2% | 32.8% | 50.2% |
| Never Married | 24.0% | 20.3% | 33.8% |
| Divorced | 15.3% | 7.7% | 10.8% |
| Widowed | 24.9% | 4.9% | 5.6% |
| space5 | | | |
| Household Size | 1.64 | 2.64 | 2.60 |
| Households | 488 | 11,221 | 124,010,992 |
| Family Households | 241 | 8,869 | 80,755,759 |
| Married couple, w/children | 0.0% | 32.3% | 30.5% |
| Married couple, no children | 58.5% | 54.8% | 42.9% |
| Non Family Households | 247 | 2,352 | 43,255,233 |
| Single householder, w/children | 21.6% | 9.4% | 15.8% |
| Single householder, no children | 19.9% | 3.6% | 10.8% |