| Statistic | Keystone | South Dakota | National |
| Population | 542 | 884,659 | 328,239,523 |
| Population density (sq mi) | 181 | 12 | 91 |
| Median age | 30.0 | 36.8 | 37.7 |
| Male/Female ratio | 1.2:1 | 1.0:1 | 1.0:1 |
| Married (15yrs & older) | 45% | 59% | 55% |
| Families w/ Kids under 18 | 49% | 44% | 43% |
| Speak English | 78% | 94% | 79% |
| Speak Spanish | 19% | 2% | 13% |
| Race | Keystone | South Dakota | National |
| White | 87.64% | 84.77% | 73.35% |
| Black | 0.00% | 1.65% | 12.63% |
| Asian | 0.92% | 1.33% | 5.22% |
| American Indian | 2.03% | 8.72% | 0.82% |
| Native Hawaiian | 0.37% | 0.04% | 0.18% |
| Mixed race | 8.67% | 2.61% | 3.06% |
| Other race | 0.37% | 0.88% | 4.75% |
Here are the best places to live in South Dakota
Most Dangerous States In The US
Check out the 10 most dangerous cities in South Dakota
Safest States In The US