| | Richardton, ND | Bismarck, ND | United States |
| Population | 896 | 73,321 | 329,725,481 |
| Female Population | 54.7% | 50.7% | 50.5% |
| Male Population | 45.3% | 49.4% | 49.5% |
| Median Age | 38.1 | 37.6 | 38.4 |
| space3 | | | |
| Population - 2010 | 527 | 61,595 | 309,327,143 |
| Population - 2000 | 619 | 55,532 | 285,036,114 |
| Population - 1990 | 625 | 49,256 | 251,960,433 |
| Pop. 2000 to Now | -7.4% | 33.3% | 15.6% |
| Pop. 1990 to Now | -8.3% | 50.3% | 30.8% |
| space4 | | | |
| Population Density | 655.0 | 2,173.3 | 93.4 |
| Land Area | 1.4 | 33.7 | 3,531,905.4 |
| Water Area | 0.0 | 0.5 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Richardton, ND | Bismarck, ND | United States |
| Age 0 to 4 | 5.5% | 6.4% | 5.9% |
| Age 5 to 9 | 6.5% | 6.2% | 6.1% |
| Age 10 to 14 | 13.7% | 6.2% | 6.6% |
| Age 15 to 17 | 6.9% | 3.5% | 3.9% |
| Age 18 to 20 | 2.5% | 4.1% | 4.0% |
| Age 21 to 24 | 0.2% | 5.0% | 5.2% |
| Age 25 to 34 | 8.6% | 14.6% | 13.8% |
| Age 35 to 44 | 12.4% | 13.4% | 12.9% |
| Age 45 to 54 | 11.6% | 10.8% | 12.6% |
| Age 55 to 59 | 12.2% | 5.9% | 6.7% |
| Age 60 to 64 | 5.5% | 6.7% | 6.3% |
| Age 65 to 74 | 9.4% | 9.3% | 9.6% |
| Age 75 to 84 | 3.5% | 5.2% | 4.5% |
| Age 85 and over | 1.7% | 2.7% | 1.9% |
| space1 | | | |
| Race | | | |
| | Richardton, ND | Bismarck, ND | United States |
| White | 88.6% | 85.7% | 59.4% |
| Black | 0.0% | 2.6% | 12.2% |
| Asian | 0.6% | 0.8% | 5.6% |
| Native American | 0.2% | 4.4% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.3% | 0.2% |
| Other | 1.1% | 0.1% | 0.4% |
| Two or More Races | 5.7% | 3.7% | 3.2% |
| Hispanic | 3.8% | 2.4% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Richardton, ND | Bismarck, ND | United States |
| Married Population | 51.5% | 49.4% | 49.8% |
| Currently Married | 51.2% | 48.5% | 48.0% |
| Married but Separated | 0.3% | 0.9% | 1.8% |
| Single Population | 48.5% | 50.6% | 50.2% |
| Never Married | 26.6% | 33.1% | 33.8% |
| Divorced | 18.9% | 11.4% | 10.8% |
| Widowed | 3.0% | 6.1% | 5.6% |
| space5 | | | |
| Household Size | 2.49 | 2.28 | 2.60 |
| Households | 360 | 31,227 | 124,010,992 |
| Family Households | 264 | 17,997 | 80,755,759 |
| Married couple, w/children | 24.6% | 31.9% | 30.5% |
| Married couple, no children | 37.9% | 45.2% | 42.9% |
| Non Family Households | 96 | 13,230 | 43,255,233 |
| Single householder, w/children | 36.7% | 16.6% | 15.8% |
| Single householder, no children | 0.8% | 6.4% | 10.8% |