| | Running Springs, CA | Glendora, CA | United States |
| Population | 3,998 | 52,458 | 329,725,481 |
| Female Population | 50.8% | 52.0% | 50.5% |
| Male Population | 49.2% | 48.0% | 49.5% |
| Median Age | 42.2 | 40 | 38.4 |
| space3 | | | |
| Population - 2010 | 5,068 | 50,258 | 309,327,143 |
| Population - 2000 | 5,125 | 49,415 | 285,036,114 |
| Population - 1990 | 4,195 | 47,828 | 251,960,433 |
| Pop. 2000 to Now | -10.6% | 2.2% | 15.6% |
| Pop. 1990 to Now | 9.3% | 5.6% | 30.8% |
| space4 | | | |
| Population Density | 951.0 | 2,688.9 | 93.4 |
| Land Area | 4.2 | 19.5 | 3,531,905.4 |
| Water Area | 0.0 | 0.2 | 264,836.8 |
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| Est. Total Population By Age | | | |
| | Running Springs, CA | Glendora, CA | United States |
| Age 0 to 4 | 7.3% | 5.3% | 5.9% |
| Age 5 to 9 | 4.8% | 5.7% | 6.1% |
| Age 10 to 14 | 7.6% | 7.3% | 6.6% |
| Age 15 to 17 | 3.1% | 4.6% | 3.9% |
| Age 18 to 20 | 1.1% | 3.3% | 4.0% |
| Age 21 to 24 | 4.2% | 4.5% | 5.2% |
| Age 25 to 34 | 13.9% | 12.7% | 13.8% |
| Age 35 to 44 | 12.6% | 13.5% | 12.9% |
| Age 45 to 54 | 11.6% | 13.3% | 12.6% |
| Age 55 to 59 | 4.9% | 7.9% | 6.7% |
| Age 60 to 64 | 5.5% | 6.3% | 6.3% |
| Age 65 to 74 | 17.6% | 8.9% | 9.6% |
| Age 75 to 84 | 5.3% | 4.6% | 4.5% |
| Age 85 and over | 0.6% | 2.1% | 1.9% |
| space1 | | | |
| Race | | | |
| | Running Springs, CA | Glendora, CA | United States |
| White | 70.3% | 43.9% | 59.4% |
| Black | 0.4% | 2.1% | 12.2% |
| Asian | 3.2% | 11.6% | 5.6% |
| Native American | 1.0% | 0.4% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.2% | 0.2% |
| Other | 0.0% | 0.4% | 0.4% |
| Two or More Races | 4.2% | 3.2% | 3.2% |
| Hispanic | 20.9% | 38.2% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Running Springs, CA | Glendora, CA | United States |
| Married Population | 53.8% | 52.9% | 49.8% |
| Currently Married | 52.4% | 52.0% | 48.0% |
| Married but Separated | 1.4% | 1.0% | 1.8% |
| Single Population | 46.2% | 47.1% | 50.2% |
| Never Married | 23.3% | 33.0% | 33.8% |
| Divorced | 17.7% | 9.5% | 10.8% |
| Widowed | 5.2% | 4.6% | 5.6% |
| space5 | | | |
| Household Size | 2.53 | 3.05 | 2.60 |
| Households | 1,580 | 16,861 | 124,010,992 |
| Family Households | 1,019 | 13,036 | 80,755,759 |
| Married couple, w/children | 31.4% | 35.0% | 30.5% |
| Married couple, no children | 45.6% | 41.1% | 42.9% |
| Non Family Households | 561 | 3,825 | 43,255,233 |
| Single householder, w/children | 12.4% | 11.7% | 15.8% |
| Single householder, no children | 10.6% | 12.2% | 10.8% |