| | Williams, OR | Placerville, CA | United States |
| Population | 1,033 | 10,777 | 329,725,481 |
| Female Population | 47.7% | 55.1% | 50.5% |
| Male Population | 52.3% | 44.9% | 49.5% |
| Median Age | 47.3 | 43.3 | 38.4 |
| space3 | | | |
| Population - 2010 | 1,365 | 10,470 | 309,327,143 |
| Population - 2000 | 1,113 | 9,610 | 285,036,114 |
| Population - 1990 | 933 | 8,355 | 251,960,433 |
| Pop. 2000 to Now | 7.9% | 15.3% | 15.6% |
| Pop. 1990 to Now | 28.7% | 32.6% | 30.8% |
| space4 | | | |
| Population Density | 91.2 | 1,845.4 | 93.4 |
| Land Area | 11.3 | 5.8 | 3,531,905.4 |
| Water Area | 0.0 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Williams, OR | Placerville, CA | United States |
| Age 0 to 4 | 6.4% | 4.9% | 5.9% |
| Age 5 to 9 | 10.0% | 5.7% | 6.1% |
| Age 10 to 14 | 3.0% | 5.6% | 6.6% |
| Age 15 to 17 | 2.7% | 3.8% | 3.9% |
| Age 18 to 20 | 0.9% | 1.9% | 4.0% |
| Age 21 to 24 | 0.9% | 3.7% | 5.2% |
| Age 25 to 34 | 14.9% | 16.4% | 13.8% |
| Age 35 to 44 | 9.1% | 10.4% | 12.9% |
| Age 45 to 54 | 8.1% | 11.7% | 12.6% |
| Age 55 to 59 | 7.2% | 7.8% | 6.7% |
| Age 60 to 64 | 4.1% | 8.4% | 6.3% |
| Age 65 to 74 | 17.5% | 11.9% | 9.6% |
| Age 75 to 84 | 14.3% | 5.1% | 4.5% |
| Age 85 and over | 1.0% | 2.8% | 1.9% |
| space1 | | | |
| Race | | | |
| | Williams, OR | Placerville, CA | United States |
| White | 98.7% | 74.9% | 59.4% |
| Black | 0.0% | 0.9% | 12.2% |
| Asian | 0.0% | 0.9% | 5.6% |
| Native American | 0.0% | 0.7% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 0.0% | 0.4% |
| Two or More Races | 0.8% | 3.2% | 3.2% |
| Hispanic | 0.5% | 19.3% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Williams, OR | Placerville, CA | United States |
| Married Population | 61.1% | 48.1% | 49.8% |
| Currently Married | 61.1% | 45.7% | 48.0% |
| Married but Separated | 0.0% | 2.5% | 1.8% |
| Single Population | 38.9% | 51.9% | 50.2% |
| Never Married | 19.7% | 28.4% | 33.8% |
| Divorced | 18.0% | 16.8% | 10.8% |
| Widowed | 1.2% | 6.7% | 5.6% |
| space5 | | | |
| Household Size | 2.39 | 2.25 | 2.60 |
| Households | 433 | 4,500 | 124,010,992 |
| Family Households | 310 | 2,778 | 80,755,759 |
| Married couple, w/children | 15.5% | 27.4% | 30.5% |
| Married couple, no children | 57.4% | 38.5% | 42.9% |
| Non Family Households | 123 | 1,722 | 43,255,233 |
| Single householder, w/children | 23.9% | 20.5% | 15.8% |
| Single householder, no children | 3.2% | 13.6% | 10.8% |