| | River Falls, WI | Mandan, ND | United States |
| Population | 16,058 | 23,784 | 329,725,481 |
| Female Population | 53.2% | 49.4% | 50.5% |
| Male Population | 46.8% | 50.6% | 49.5% |
| Median Age | 26.8 | 35.5 | 38.4 |
| space3 | | | |
| Population - 2010 | 15,041 | 18,948 | 309,327,143 |
| Population - 2000 | 12,560 | 16,718 | 285,036,114 |
| Population - 1990 | 10,610 | 15,177 | 251,960,433 |
| Pop. 2000 to Now | 29.8% | 36.7% | 15.6% |
| Pop. 1990 to Now | 53.7% | 50.6% | 30.8% |
| space4 | | | |
| Population Density | 2,300.9 | 1,761.4 | 93.4 |
| Land Area | 7.0 | 13.5 | 3,531,905.4 |
| Water Area | 0.1 | 0.1 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | River Falls, WI | Mandan, ND | United States |
| Age 0 to 4 | 3.6% | 5.9% | 5.9% |
| Age 5 to 9 | 4.6% | 6.3% | 6.1% |
| Age 10 to 14 | 6.5% | 6.7% | 6.6% |
| Age 15 to 17 | 2.2% | 3.8% | 3.9% |
| Age 18 to 20 | 15.9% | 4.0% | 4.0% |
| Age 21 to 24 | 15.5% | 5.7% | 5.2% |
| Age 25 to 34 | 12.3% | 16.4% | 13.8% |
| Age 35 to 44 | 10.9% | 12.6% | 12.9% |
| Age 45 to 54 | 8.8% | 12.1% | 12.6% |
| Age 55 to 59 | 4.1% | 6.1% | 6.7% |
| Age 60 to 64 | 4.6% | 5.6% | 6.3% |
| Age 65 to 74 | 6.9% | 9.6% | 9.6% |
| Age 75 to 84 | 2.6% | 3.6% | 4.5% |
| Age 85 and over | 1.5% | 1.6% | 1.9% |
| space1 | | | |
| Race | | | |
| | River Falls, WI | Mandan, ND | United States |
| White | 90.9% | 85.5% | 59.4% |
| Black | 1.2% | 1.6% | 12.2% |
| Asian | 2.2% | 1.2% | 5.6% |
| Native American | 0.3% | 4.5% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.1% | 0.2% |
| Other | 0.0% | 0.3% | 0.4% |
| Two or More Races | 2.5% | 2.1% | 3.2% |
| Hispanic | 2.9% | 4.8% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | River Falls, WI | Mandan, ND | United States |
| Married Population | 35.2% | 55.2% | 49.8% |
| Currently Married | 34.9% | 54.6% | 48.0% |
| Married but Separated | 0.3% | 0.5% | 1.8% |
| Single Population | 64.8% | 44.8% | 50.2% |
| Never Married | 53.2% | 30.4% | 33.8% |
| Divorced | 8.3% | 9.5% | 10.8% |
| Widowed | 3.3% | 4.9% | 5.6% |
| space5 | | | |
| Household Size | 2.45 | 2.41 | 2.60 |
| Households | 5,537 | 9,697 | 124,010,992 |
| Family Households | 3,005 | 6,423 | 80,755,759 |
| Married couple, w/children | 34.1% | 31.2% | 30.5% |
| Married couple, no children | 42.7% | 48.3% | 42.9% |
| Non Family Households | 2,532 | 3,274 | 43,255,233 |
| Single householder, w/children | 13.3% | 14.2% | 15.8% |
| Single householder, no children | 9.9% | 6.3% | 10.8% |