| | Adin, CA | Grizzly Flats, CA | United States |
| Population | 171 | 1,205 | 329,725,481 |
| Female Population | 48.0% | 51.7% | 50.5% |
| Male Population | 52.1% | 48.3% | 49.5% |
| Median Age | 67.2 | 45 | 38.4 |
| space3 | | | |
| Population - 2010 | 374 | 793 | 309,327,143 |
| Population - 2000 | 251 | 673 | 285,036,114 |
| Population - 1990 | 249 | 475 | 251,960,433 |
| Pop. 2000 to Now | -20.7% | 48.1% | 15.6% |
| Pop. 1990 to Now | -20.1% | 109.9% | 30.8% |
| space4 | | | |
| Population Density | 49.8 | 181.8 | 93.4 |
| Land Area | 3.4 | 6.6 | 3,531,905.4 |
| Water Area | 0.0 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Adin, CA | Grizzly Flats, CA | United States |
| Age 0 to 4 | 5.3% | 0.0% | 5.9% |
| Age 5 to 9 | 0.0% | 10.3% | 6.1% |
| Age 10 to 14 | 0.0% | 15.0% | 6.6% |
| Age 15 to 17 | 0.0% | 5.8% | 3.9% |
| Age 18 to 20 | 12.3% | 0.0% | 4.0% |
| Age 21 to 24 | 1.2% | 1.0% | 5.2% |
| Age 25 to 34 | 0.0% | 3.2% | 13.8% |
| Age 35 to 44 | 9.4% | 15.0% | 12.9% |
| Age 45 to 54 | 9.9% | 8.1% | 12.6% |
| Age 55 to 59 | 3.5% | 10.0% | 6.7% |
| Age 60 to 64 | 7.6% | 3.7% | 6.3% |
| Age 65 to 74 | 11.1% | 23.3% | 9.6% |
| Age 75 to 84 | 18.7% | 3.2% | 4.5% |
| Age 85 and over | 21.1% | 1.3% | 1.9% |
| space1 | | | |
| Race | | | |
| | Adin, CA | Grizzly Flats, CA | United States |
| White | 82.5% | 89.1% | 59.4% |
| Black | 0.0% | 0.0% | 12.2% |
| Asian | 0.6% | 0.0% | 5.6% |
| Native American | 16.4% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 0.0% | 0.4% |
| Two or More Races | 0.0% | 10.5% | 3.2% |
| Hispanic | 0.6% | 0.3% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Adin, CA | Grizzly Flats, CA | United States |
| Married Population | 45.1% | 77.1% | 49.8% |
| Currently Married | 45.1% | 77.1% | 48.0% |
| Married but Separated | 0.0% | 0.0% | 1.8% |
| Single Population | 54.9% | 22.9% | 50.2% |
| Never Married | 29.0% | 11.1% | 33.8% |
| Divorced | 17.3% | 8.8% | 10.8% |
| Widowed | 8.6% | 3.0% | 5.6% |
| space5 | | | |
| Household Size | 1.73 | 2.42 | 2.60 |
| Households | 82 | 497 | 124,010,992 |
| Family Households | 43 | 349 | 80,755,759 |
| Married couple, w/children | 20.9% | 58.7% | 30.5% |
| Married couple, no children | 79.1% | 41.3% | 42.9% |
| Non Family Households | 39 | 148 | 43,255,233 |
| Single householder, w/children | 0.0% | 0.0% | 15.8% |
| Single householder, no children | 0.0% | 0.0% | 10.8% |