| | Forsyth, MT | Busby, MT | United States |
| Population | 1,562 | 496 | 329,725,481 |
| Female Population | 47.0% | 53.2% | 50.5% |
| Male Population | 53.0% | 46.8% | 49.5% |
| Median Age | 36.5 | 25.7 | 38.4 |
| space3 | | | |
| Population - 2010 | 1,860 | 409 | 309,327,143 |
| Population - 2000 | 1,944 | 695 | 285,036,114 |
| Population - 1990 | 2,178 | 409 | 251,960,433 |
| Pop. 2000 to Now | -9.9% | -8.5% | 15.6% |
| Pop. 1990 to Now | -19.6% | 55.5% | 30.8% |
| space4 | | | |
| Population Density | 1,355.9 | 34.6 | 93.4 |
| Land Area | 1.2 | 14.4 | 3,531,905.4 |
| Water Area | 0.0 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Forsyth, MT | Busby, MT | United States |
| Age 0 to 4 | 7.2% | 9.9% | 5.9% |
| Age 5 to 9 | 4.8% | 11.9% | 6.1% |
| Age 10 to 14 | 5.4% | 8.1% | 6.6% |
| Age 15 to 17 | 1.6% | 7.5% | 3.9% |
| Age 18 to 20 | 7.0% | 0.0% | 4.0% |
| Age 21 to 24 | 6.4% | 8.5% | 5.2% |
| Age 25 to 34 | 16.6% | 9.9% | 13.8% |
| Age 35 to 44 | 4.8% | 10.5% | 12.9% |
| Age 45 to 54 | 5.7% | 14.3% | 12.6% |
| Age 55 to 59 | 4.8% | 12.9% | 6.7% |
| Age 60 to 64 | 7.0% | 1.4% | 6.3% |
| Age 65 to 74 | 19.4% | 5.0% | 9.6% |
| Age 75 to 84 | 8.9% | 0.2% | 4.5% |
| Age 85 and over | 0.3% | 0.0% | 1.9% |
| space1 | | | |
| Race | | | |
| | Forsyth, MT | Busby, MT | United States |
| White | 78.2% | 2.2% | 59.4% |
| Black | 0.0% | 0.0% | 12.2% |
| Asian | 1.5% | 0.0% | 5.6% |
| Native American | 1.5% | 87.5% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 0.0% | 0.4% |
| Two or More Races | 12.8% | 1.6% | 3.2% |
| Hispanic | 6.1% | 8.7% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Forsyth, MT | Busby, MT | United States |
| Married Population | 53.5% | 48.0% | 49.8% |
| Currently Married | 53.1% | 42.5% | 48.0% |
| Married but Separated | 0.4% | 5.5% | 1.8% |
| Single Population | 46.5% | 52.0% | 50.2% |
| Never Married | 33.6% | 35.9% | 33.8% |
| Divorced | 8.9% | 12.6% | 10.8% |
| Widowed | 4.0% | 3.4% | 5.6% |
| space5 | | | |
| Household Size | 2.46 | 4.59 | 2.60 |
| Households | 608 | 104 | 124,010,992 |
| Family Households | 371 | 78 | 80,755,759 |
| Married couple, w/children | 19.7% | 60.3% | 30.5% |
| Married couple, no children | 64.7% | 7.7% | 42.9% |
| Non Family Households | 237 | 26 | 43,255,233 |
| Single householder, w/children | 12.4% | 32.1% | 15.8% |
| Single householder, no children | 3.2% | 0.0% | 10.8% |