| | Mammoth, WY | Estes Park, CO | United States |
| Population | 59 | 5,942 | 329,725,481 |
| Female Population | 25.4% | 53.1% | 50.5% |
| Male Population | 74.6% | 46.9% | 49.5% |
| Median Age | 76 | 60.1 | 38.4 |
| space3 | | | |
| Population - 2010 | 218 | 5,944 | 309,327,143 |
| Population - 2000 | 182 | 5,413 | 285,036,114 |
| Population - 1990 | 140 | 3,184 | 251,960,433 |
| Pop. 2000 to Now | -68.1% | 21.1% | 15.6% |
| Pop. 1990 to Now | -58.6% | 105.8% | 30.8% |
| space4 | | | |
| Population Density | 74.9 | 860.9 | 93.4 |
| Land Area | 0.8 | 6.9 | 3,531,905.4 |
| Water Area | 0.0 | 0.1 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Mammoth, WY | Estes Park, CO | United States |
| Age 0 to 4 | 0.0% | 0.7% | 5.9% |
| Age 5 to 9 | 0.0% | 4.2% | 6.1% |
| Age 10 to 14 | 0.0% | 2.6% | 6.6% |
| Age 15 to 17 | 0.0% | 2.0% | 3.9% |
| Age 18 to 20 | 0.0% | 2.4% | 4.0% |
| Age 21 to 24 | 8.5% | 3.2% | 5.2% |
| Age 25 to 34 | 13.6% | 11.0% | 13.8% |
| Age 35 to 44 | 8.5% | 5.5% | 12.9% |
| Age 45 to 54 | 5.1% | 12.2% | 12.6% |
| Age 55 to 59 | 10.2% | 6.1% | 6.7% |
| Age 60 to 64 | 0.0% | 12.3% | 6.3% |
| Age 65 to 74 | 3.4% | 27.3% | 9.6% |
| Age 75 to 84 | 50.8% | 6.7% | 4.5% |
| Age 85 and over | 0.0% | 3.8% | 1.9% |
| space1 | | | |
| Race | | | |
| | Mammoth, WY | Estes Park, CO | United States |
| White | 94.9% | 87.1% | 59.4% |
| Black | 0.0% | 1.2% | 12.2% |
| Asian | 0.0% | 0.0% | 5.6% |
| Native American | 0.0% | 0.4% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 0.8% | 0.4% |
| Two or More Races | 1.7% | 0.6% | 3.2% |
| Hispanic | 3.4% | 10.0% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Mammoth, WY | Estes Park, CO | United States |
| Married Population | 5.1% | 58.5% | 49.8% |
| Currently Married | 5.1% | 58.5% | 48.0% |
| Married but Separated | 0.0% | 0.0% | 1.8% |
| Single Population | 94.9% | 41.5% | 50.2% |
| Never Married | 72.9% | 14.7% | 33.8% |
| Divorced | 16.9% | 19.9% | 10.8% |
| Widowed | 5.1% | 6.9% | 5.6% |
| space5 | | | |
| Household Size | | 1.87 | 2.6 |