| | Mammoth Spring, AR | Bella Vista, AR | United States |
| Population | 1,173 | 29,818 | 329,725,481 |
| Female Population | 47.8% | 50.0% | 50.5% |
| Male Population | 52.2% | 50.0% | 49.5% |
| Median Age | 37.8 | 50.9 | 38.4 |
| space3 | | | |
| Population - 2010 | 958 | 26,592 | 309,327,143 |
| Population - 2000 | 1,147 | 16,582 | 285,036,114 |
| Population - 1990 | 1,097 | 9,083 | 251,960,433 |
| Pop. 2000 to Now | -18.1% | 77.4% | 15.6% |
| Pop. 1990 to Now | -14.3% | 223.9% | 30.8% |
| space4 | | | |
| Population Density | 908.6 | 658.5 | 93.4 |
| Land Area | 1.3 | 45.3 | 3,531,905.4 |
| Water Area | 0.0 | 1.6 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Mammoth Spring, AR | Bella Vista, AR | United States |
| Age 0 to 4 | 9.0% | 4.1% | 5.9% |
| Age 5 to 9 | 5.0% | 4.9% | 6.1% |
| Age 10 to 14 | 11.8% | 4.9% | 6.6% |
| Age 15 to 17 | 3.7% | 4.2% | 3.9% |
| Age 18 to 20 | 4.3% | 2.1% | 4.0% |
| Age 21 to 24 | 2.6% | 2.1% | 5.2% |
| Age 25 to 34 | 10.1% | 9.1% | 13.8% |
| Age 35 to 44 | 16.4% | 13.3% | 12.9% |
| Age 45 to 54 | 7.7% | 8.8% | 12.6% |
| Age 55 to 59 | 6.0% | 6.5% | 6.7% |
| Age 60 to 64 | 4.0% | 8.2% | 6.3% |
| Age 65 to 74 | 10.7% | 17.0% | 9.6% |
| Age 75 to 84 | 6.7% | 11.4% | 4.5% |
| Age 85 and over | 2.0% | 3.3% | 1.9% |
| space1 | | | |
| Race | | | |
| | Mammoth Spring, AR | Bella Vista, AR | United States |
| White | 93.1% | 87.8% | 59.4% |
| Black | 0.0% | 0.4% | 12.2% |
| Asian | 0.0% | 0.9% | 5.6% |
| Native American | 1.8% | 0.8% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 0.2% | 0.4% |
| Two or More Races | 5.1% | 6.6% | 3.2% |
| Hispanic | 0.0% | 3.4% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Mammoth Spring, AR | Bella Vista, AR | United States |
| Married Population | 50.1% | 67.2% | 49.8% |
| Currently Married | 48.0% | 66.0% | 48.0% |
| Married but Separated | 2.1% | 1.2% | 1.8% |
| Single Population | 49.9% | 32.8% | 50.2% |
| Never Married | 23.9% | 16.2% | 33.8% |
| Divorced | 18.7% | 9.8% | 10.8% |
| Widowed | 7.2% | 6.9% | 5.6% |
| space5 | | | |
| Household Size | 2.85 | 2.40 | 2.60 |
| Households | 412 | 12,382 | 124,010,992 |
| Family Households | 252 | 9,075 | 80,755,759 |
| Married couple, w/children | 45.2% | 25.9% | 30.5% |
| Married couple, no children | 31.0% | 63.3% | 42.9% |
| Non Family Households | 160 | 3,307 | 43,255,233 |
| Single householder, w/children | 13.1% | 5.8% | 15.8% |
| Single householder, no children | 10.7% | 5.0% | 10.8% |