| | Moore, MT | Marion, MT | United States |
| Population | 207 | 1,219 | 329,725,481 |
| Female Population | 46.4% | 43.4% | 50.5% |
| Male Population | 53.6% | 56.6% | 49.5% |
| Median Age | 46.3 | 47.9 | 38.4 |
| space3 | | | |
| Population - 2010 | 187 | 478 | 309,327,143 |
| Population - 2000 | 186 | 483 | 285,036,114 |
| Population - 1990 | 211 | 295 | 251,960,433 |
| Pop. 2000 to Now | -2.2% | 106.4% | 15.6% |
| Pop. 1990 to Now | -13.7% | 238.0% | 30.8% |
| space4 | | | |
| Population Density | 708.9 | 72.3 | 93.4 |
| Land Area | 0.3 | 16.9 | 3,531,905.4 |
| Water Area | 0.0 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Moore, MT | Marion, MT | United States |
| Age 0 to 4 | 7.2% | 4.2% | 5.9% |
| Age 5 to 9 | 7.2% | 7.8% | 6.1% |
| Age 10 to 14 | 2.4% | 3.8% | 6.6% |
| Age 15 to 17 | 4.8% | 7.4% | 3.9% |
| Age 18 to 20 | 4.3% | 3.5% | 4.0% |
| Age 21 to 24 | 3.4% | 2.2% | 5.2% |
| Age 25 to 34 | 6.8% | 4.8% | 13.8% |
| Age 35 to 44 | 13.5% | 11.7% | 12.9% |
| Age 45 to 54 | 9.2% | 22.2% | 12.6% |
| Age 55 to 59 | 4.3% | 12.8% | 6.7% |
| Age 60 to 64 | 7.2% | 8.9% | 6.3% |
| Age 65 to 74 | 15.9% | 9.2% | 9.6% |
| Age 75 to 84 | 9.7% | 1.3% | 4.5% |
| Age 85 and over | 3.9% | 0.2% | 1.9% |
| space1 | | | |
| Race | | | |
| | Moore, MT | Marion, MT | United States |
| White | 79.7% | 89.9% | 59.4% |
| Black | 0.0% | 0.0% | 12.2% |
| Asian | 0.0% | 0.6% | 5.6% |
| Native American | 3.4% | 0.4% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 0.0% | 0.4% |
| Two or More Races | 13.0% | 7.1% | 3.2% |
| Hispanic | 3.9% | 2.1% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Moore, MT | Marion, MT | United States |
| Married Population | 58.1% | 64.9% | 49.8% |
| Currently Married | 58.1% | 64.9% | 48.0% |
| Married but Separated | 0.0% | 0.0% | 1.8% |
| Single Population | 41.9% | 35.1% | 50.2% |
| Never Married | 23.8% | 20.3% | 33.8% |
| Divorced | 13.4% | 10.2% | 10.8% |
| Widowed | 4.7% | 4.6% | 5.6% |
| space5 | | | |
| Household Size | 2.33 | 2.95 | 2.60 |
| Households | 89 | 413 | 124,010,992 |
| Family Households | 71 | 333 | 80,755,759 |
| Married couple, w/children | 22.5% | 24.0% | 30.5% |
| Married couple, no children | 47.9% | 59.8% | 42.9% |
| Non Family Households | 18 | 80 | 43,255,233 |
| Single householder, w/children | 25.4% | 12.0% | 15.8% |
| Single householder, no children | 4.2% | 4.2% | 10.8% |