| | Marion, MT | Echo, OR | United States |
| Population | 1,219 | 572 | 329,725,481 |
| Female Population | 43.4% | 51.6% | 50.5% |
| Male Population | 56.6% | 48.4% | 49.5% |
| Median Age | 47.9 | 34.8 | 38.4 |
| space3 | | | |
| Population - 2010 | 478 | 697 | 309,327,143 |
| Population - 2000 | 483 | 650 | 285,036,114 |
| Population - 1990 | 295 | 499 | 251,960,433 |
| Pop. 2000 to Now | 106.4% | 8.5% | 15.6% |
| Pop. 1990 to Now | 238.0% | 41.3% | 30.8% |
| space4 | | | |
| Population Density | 72.3 | 987.9 | 93.4 |
| Land Area | 16.9 | 0.6 | 3,531,905.4 |
| Water Area | 0.0 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Marion, MT | Echo, OR | United States |
| Age 0 to 4 | 4.2% | 8.6% | 5.9% |
| Age 5 to 9 | 7.8% | 6.6% | 6.1% |
| Age 10 to 14 | 3.8% | 9.6% | 6.6% |
| Age 15 to 17 | 7.4% | 3.3% | 3.9% |
| Age 18 to 20 | 3.5% | 2.8% | 4.0% |
| Age 21 to 24 | 2.2% | 3.1% | 5.2% |
| Age 25 to 34 | 4.8% | 16.4% | 13.8% |
| Age 35 to 44 | 11.7% | 12.8% | 12.9% |
| Age 45 to 54 | 22.2% | 12.9% | 12.6% |
| Age 55 to 59 | 12.8% | 6.6% | 6.7% |
| Age 60 to 64 | 8.9% | 7.5% | 6.3% |
| Age 65 to 74 | 9.2% | 5.6% | 9.6% |
| Age 75 to 84 | 1.3% | 3.0% | 4.5% |
| Age 85 and over | 0.2% | 1.0% | 1.9% |
| space1 | | | |
| Race | | | |
| | Marion, MT | Echo, OR | United States |
| White | 89.9% | 83.9% | 59.4% |
| Black | 0.0% | 0.0% | 12.2% |
| Asian | 0.6% | 0.0% | 5.6% |
| Native American | 0.4% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 0.0% | 0.4% |
| Two or More Races | 7.1% | 8.2% | 3.2% |
| Hispanic | 2.1% | 7.9% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Marion, MT | Echo, OR | United States |
| Married Population | 64.9% | 69.5% | 49.8% |
| Currently Married | 64.9% | 69.5% | 48.0% |
| Married but Separated | 0.0% | 0.0% | 1.8% |
| Single Population | 35.1% | 30.5% | 50.2% |
| Never Married | 20.3% | 20.9% | 33.8% |
| Divorced | 10.2% | 7.4% | 10.8% |
| Widowed | 4.6% | 2.1% | 5.6% |
| space5 | | | |
| Household Size | 2.95 | 2.74 | 2.60 |
| Households | 413 | 209 | 124,010,992 |
| Family Households | 333 | 163 | 80,755,759 |
| Married couple, w/children | 24.0% | 35.6% | 30.5% |
| Married couple, no children | 59.8% | 50.9% | 42.9% |
| Non Family Households | 80 | 46 | 43,255,233 |
| Single householder, w/children | 12.0% | 10.4% | 15.8% |
| Single householder, no children | 4.2% | 3.1% | 10.8% |