| | Riverton, WY | Stevensville, MT | United States |
| Population | 10,619 | 1,959 | 329,725,481 |
| Female Population | 49.5% | 52.7% | 50.5% |
| Male Population | 50.5% | 47.3% | 49.5% |
| Median Age | 37.1 | 40.2 | 38.4 |
| space3 | | | |
| Population - 2010 | 10,780 | 1,837 | 309,327,143 |
| Population - 2000 | 9,310 | 1,553 | 285,036,114 |
| Population - 1990 | 9,202 | 1,221 | 251,960,433 |
| Pop. 2000 to Now | 16.2% | 37.7% | 15.6% |
| Pop. 1990 to Now | 17.6% | 75.1% | 30.8% |
| space4 | | | |
| Population Density | 893.8 | 1,512.7 | 93.4 |
| Land Area | 11.9 | 1.3 | 3,531,905.4 |
| Water Area | 0.0 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Riverton, WY | Stevensville, MT | United States |
| Age 0 to 4 | 6.0% | 6.6% | 5.9% |
| Age 5 to 9 | 6.8% | 8.6% | 6.1% |
| Age 10 to 14 | 8.5% | 5.3% | 6.6% |
| Age 15 to 17 | 3.5% | 3.9% | 3.9% |
| Age 18 to 20 | 4.6% | 4.8% | 4.0% |
| Age 21 to 24 | 4.1% | 4.0% | 5.2% |
| Age 25 to 34 | 13.1% | 8.7% | 13.8% |
| Age 35 to 44 | 12.4% | 14.2% | 12.9% |
| Age 45 to 54 | 12.3% | 12.8% | 12.6% |
| Age 55 to 59 | 6.0% | 4.4% | 6.7% |
| Age 60 to 64 | 7.4% | 7.4% | 6.3% |
| Age 65 to 74 | 8.2% | 9.4% | 9.6% |
| Age 75 to 84 | 4.8% | 7.3% | 4.5% |
| Age 85 and over | 2.3% | 2.7% | 1.9% |
| space1 | | | |
| Race | | | |
| | Riverton, WY | Stevensville, MT | United States |
| White | 72.0% | 94.2% | 59.4% |
| Black | 0.8% | 0.2% | 12.2% |
| Asian | 1.0% | 0.0% | 5.6% |
| Native American | 8.3% | 1.1% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 0.0% | 0.4% |
| Two or More Races | 3.4% | 2.6% | 3.2% |
| Hispanic | 14.5% | 1.9% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Riverton, WY | Stevensville, MT | United States |
| Married Population | 44.9% | 40.6% | 49.8% |
| Currently Married | 42.8% | 38.4% | 48.0% |
| Married but Separated | 2.1% | 2.2% | 1.8% |
| Single Population | 55.1% | 59.4% | 50.2% |
| Never Married | 31.8% | 30.4% | 33.8% |
| Divorced | 16.9% | 20.9% | 10.8% |
| Widowed | 6.4% | 8.1% | 5.6% |
| space5 | | | |
| Household Size | 2.45 | 2.12 | 2.60 |
| Households | 4,146 | 907 | 124,010,992 |
| Family Households | 2,357 | 416 | 80,755,759 |
| Married couple, w/children | 23.5% | 23.1% | 30.5% |
| Married couple, no children | 48.8% | 42.3% | 42.9% |
| Non Family Households | 1,789 | 491 | 43,255,233 |
| Single householder, w/children | 23.0% | 28.1% | 15.8% |
| Single householder, no children | 4.7% | 6.5% | 10.8% |