| | Big Sky, MT | Island Park, ID | United States |
| Population | 3,141 | 184 | 329,725,481 |
| Female Population | 49.5% | 35.3% | 50.5% |
| Male Population | 50.5% | 64.7% | 49.5% |
| Median Age | 36.6 | 62.7 | 38.4 |
| space3 | | | |
| Population - 2010 | 1,528 | 272 | 309,327,143 |
| Population - 2000 | 1,221 | 215 | 285,036,114 |
| Population - 1990 | 686 | 159 | 251,960,433 |
| Pop. 2000 to Now | 174.9% | 20.9% | 15.6% |
| Pop. 1990 to Now | 389.4% | 63.5% | 30.8% |
| space4 | | | |
| Population Density | 26.2 | 30.3 | 93.4 |
| Land Area | 120.0 | 6.1 | 3,531,905.4 |
| Water Area | 0.2 | 0.1 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Big Sky, MT | Island Park, ID | United States |
| Age 0 to 4 | 5.0% | 1.6% | 5.9% |
| Age 5 to 9 | 6.9% | 2.7% | 6.1% |
| Age 10 to 14 | 4.3% | 0.0% | 6.6% |
| Age 15 to 17 | 1.9% | 1.6% | 3.9% |
| Age 18 to 20 | 1.7% | 3.8% | 4.0% |
| Age 21 to 24 | 6.3% | 0.0% | 5.2% |
| Age 25 to 34 | 20.8% | 2.7% | 13.8% |
| Age 35 to 44 | 22.3% | 4.3% | 12.9% |
| Age 45 to 54 | 12.4% | 17.9% | 12.6% |
| Age 55 to 59 | 6.1% | 9.8% | 6.7% |
| Age 60 to 64 | 3.4% | 9.8% | 6.3% |
| Age 65 to 74 | 8.2% | 38.6% | 9.6% |
| Age 75 to 84 | 0.7% | 6.0% | 4.5% |
| Age 85 and over | 0.2% | 1.1% | 1.9% |
| space1 | | | |
| Race | | | |
| | Big Sky, MT | Island Park, ID | United States |
| White | 86.8% | 100.0% | 59.4% |
| Black | 0.1% | 0.0% | 12.2% |
| Asian | 0.3% | 0.0% | 5.6% |
| Native American | 0.5% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 0.0% | 0.4% |
| Two or More Races | 0.9% | 0.0% | 3.2% |
| Hispanic | 11.3% | 0.0% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Big Sky, MT | Island Park, ID | United States |
| Married Population | 54.4% | 51.7% | 49.8% |
| Currently Married | 54.0% | 51.7% | 48.0% |
| Married but Separated | 0.4% | 0.0% | 1.8% |
| Single Population | 45.6% | 48.3% | 50.2% |
| Never Married | 35.6% | 7.4% | 33.8% |
| Divorced | 8.0% | 30.7% | 10.8% |
| Widowed | 2.0% | 10.2% | 5.6% |
| space5 | | | |
| Household Size | 2.33 | 2.07 | 2.60 |
| Households | 1,193 | 89 | 124,010,992 |
| Family Households | 767 | 46 | 80,755,759 |
| Married couple, w/children | 33.1% | 28.3% | 30.5% |
| Married couple, no children | 53.2% | 65.2% | 42.9% |
| Non Family Households | 426 | 43 | 43,255,233 |
| Single householder, w/children | 9.6% | 6.5% | 15.8% |
| Single householder, no children | 4.0% | 0.0% | 10.8% |