| | Roslyn, SD | Clear Lake, SD | United States |
| Population | 177 | 1,396 | 329,725,481 |
| Female Population | 55.4% | 50.9% | 50.5% |
| Male Population | 44.6% | 49.1% | 49.5% |
| Median Age | 44.3 | 44.3 | 38.4 |
| space3 | | | |
| Population - 2010 | 183 | 1,271 | 309,327,143 |
| Population - 2000 | 225 | 1,335 | 285,036,114 |
| Population - 1990 | 251 | 1,247 | 251,960,433 |
| Pop. 2000 to Now | -26.7% | -5.6% | 15.6% |
| Pop. 1990 to Now | -34.3% | 1.0% | 30.8% |
| space4 | | | |
| Population Density | 898.5 | 451.2 | 93.4 |
| Land Area | 0.2 | 3.1 | 3,531,905.4 |
| Water Area | 0.0 | 0.2 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Roslyn, SD | Clear Lake, SD | United States |
| Age 0 to 4 | 6.2% | 3.2% | 5.9% |
| Age 5 to 9 | 9.0% | 5.1% | 6.1% |
| Age 10 to 14 | 8.5% | 8.3% | 6.6% |
| Age 15 to 17 | 2.3% | 3.9% | 3.9% |
| Age 18 to 20 | 4.0% | 4.8% | 4.0% |
| Age 21 to 24 | 0.0% | 3.9% | 5.2% |
| Age 25 to 34 | 4.5% | 11.2% | 13.8% |
| Age 35 to 44 | 16.4% | 9.9% | 12.9% |
| Age 45 to 54 | 0.6% | 10.2% | 12.6% |
| Age 55 to 59 | 12.4% | 5.4% | 6.7% |
| Age 60 to 64 | 13.0% | 7.5% | 6.3% |
| Age 65 to 74 | 11.3% | 13.5% | 9.6% |
| Age 75 to 84 | 6.8% | 8.9% | 4.5% |
| Age 85 and over | 5.1% | 4.4% | 1.9% |
| space1 | | | |
| Race | | | |
| | Roslyn, SD | Clear Lake, SD | United States |
| White | 96.0% | 93.9% | 59.4% |
| Black | 0.0% | 0.1% | 12.2% |
| Asian | 0.0% | 0.0% | 5.6% |
| Native American | 2.8% | 0.5% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 0.0% | 0.4% |
| Two or More Races | 1.1% | 1.0% | 3.2% |
| Hispanic | 0.0% | 4.5% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Roslyn, SD | Clear Lake, SD | United States |
| Married Population | 48.1% | 58.2% | 49.8% |
| Currently Married | 48.1% | 58.0% | 48.0% |
| Married but Separated | 0.0% | 0.2% | 1.8% |
| Single Population | 51.9% | 41.8% | 50.2% |
| Never Married | 17.8% | 23.5% | 33.8% |
| Divorced | 24.4% | 9.5% | 10.8% |
| Widowed | 9.6% | 8.9% | 5.6% |
| space5 | | | |
| Household Size | 2.13 | 2.29 | 2.60 |
| Households | 76 | 589 | 124,010,992 |
| Family Households | 43 | 376 | 80,755,759 |
| Married couple, w/children | 23.3% | 26.9% | 30.5% |
| Married couple, no children | 55.8% | 57.4% | 42.9% |
| Non Family Households | 33 | 213 | 43,255,233 |
| Single householder, w/children | 20.9% | 13.3% | 15.8% |
| Single householder, no children | 0.0% | 2.4% | 10.8% |