| | Cascade, MT | Belt, MT | United States |
| Population | 574 | 534 | 329,725,481 |
| Female Population | 50.7% | 45.7% | 50.5% |
| Male Population | 49.3% | 54.3% | 49.5% |
| Median Age | 58.2 | 47.5 | 38.4 |
| space3 | | | |
| Population - 2010 | 687 | 580 | 309,327,143 |
| Population - 2000 | 819 | 633 | 285,036,114 |
| Population - 1990 | 729 | 571 | 251,960,433 |
| Pop. 2000 to Now | -17.3% | -10.3% | 15.6% |
| Pop. 1990 to Now | -7.1% | -0.5% | 30.8% |
| space4 | | | |
| Population Density | 875.0 | 1,579.9 | 93.4 |
| Land Area | 0.7 | 0.3 | 3,531,905.4 |
| Water Area | 0.0 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Cascade, MT | Belt, MT | United States |
| Age 0 to 4 | 7.1% | 1.1% | 5.9% |
| Age 5 to 9 | 1.7% | 3.7% | 6.1% |
| Age 10 to 14 | 6.6% | 5.8% | 6.6% |
| Age 15 to 17 | 1.6% | 5.1% | 3.9% |
| Age 18 to 20 | 2.6% | 0.0% | 4.0% |
| Age 21 to 24 | 2.1% | 7.7% | 5.2% |
| Age 25 to 34 | 9.4% | 9.2% | 13.8% |
| Age 35 to 44 | 6.1% | 16.3% | 12.9% |
| Age 45 to 54 | 8.7% | 6.9% | 12.6% |
| Age 55 to 59 | 8.4% | 4.7% | 6.7% |
| Age 60 to 64 | 5.9% | 12.5% | 6.3% |
| Age 65 to 74 | 22.6% | 12.7% | 9.6% |
| Age 75 to 84 | 12.0% | 10.7% | 4.5% |
| Age 85 and over | 5.1% | 3.6% | 1.9% |
| space1 | | | |
| Race | | | |
| | Cascade, MT | Belt, MT | United States |
| White | 77.5% | 90.4% | 59.4% |
| Black | 0.0% | 0.0% | 12.2% |
| Asian | 0.0% | 0.6% | 5.6% |
| Native American | 3.8% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 0.0% | 0.4% |
| Two or More Races | 12.7% | 0.7% | 3.2% |
| Hispanic | 5.9% | 8.2% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Cascade, MT | Belt, MT | United States |
| Married Population | 62.1% | 44.4% | 49.8% |
| Currently Married | 59.8% | 44.4% | 48.0% |
| Married but Separated | 2.3% | 0.0% | 1.8% |
| Single Population | 37.9% | 55.6% | 50.2% |
| Never Married | 21.0% | 22.9% | 33.8% |
| Divorced | 6.4% | 26.2% | 10.8% |
| Widowed | 10.5% | 6.5% | 5.6% |
| space5 | | | |
| Household Size | 2.27 | 2.39 | 2.60 |
| Households | 239 | 223 | 124,010,992 |
| Family Households | 153 | 144 | 80,755,759 |
| Married couple, w/children | 17.0% | 7.6% | 30.5% |
| Married couple, no children | 71.2% | 58.3% | 42.9% |
| Non Family Households | 86 | 79 | 43,255,233 |
| Single householder, w/children | 7.8% | 29.9% | 15.8% |
| Single householder, no children | 3.9% | 4.2% | 10.8% |