| | Mountain City, TX | Pearsall, TX | United States |
| Population | 633 | 7,888 | 329,725,481 |
| Female Population | 45.5% | 37.8% | 50.5% |
| Male Population | 54.5% | 62.2% | 49.5% |
| Median Age | 39.6 | 31.8 | 38.4 |
| space3 | | | |
| Population - 2010 | 655 | 9,178 | 309,327,143 |
| Population - 2000 | 671 | 7,157 | 285,036,114 |
| Population - 1990 | 377 | 6,924 | 251,960,433 |
| Pop. 2000 to Now | 27.9% | 48.4% | 15.6% |
| Pop. 1990 to Now | 127.6% | 53.4% | 30.8% |
| space4 | | | |
| Population Density | 1,203.4 | 1,329.5 | 93.4 |
| Land Area | 0.5 | 5.9 | 3,531,905.4 |
| Water Area | 0.0 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Mountain City, TX | Pearsall, TX | United States |
| Age 0 to 4 | 8.7% | 6.8% | 5.9% |
| Age 5 to 9 | 5.7% | 5.4% | 6.1% |
| Age 10 to 14 | 7.9% | 7.0% | 6.6% |
| Age 15 to 17 | 3.6% | 4.0% | 3.9% |
| Age 18 to 20 | 3.5% | 8.6% | 4.0% |
| Age 21 to 24 | 2.4% | 7.3% | 5.2% |
| Age 25 to 34 | 10.6% | 18.6% | 13.8% |
| Age 35 to 44 | 11.7% | 11.5% | 12.9% |
| Age 45 to 54 | 12.2% | 8.3% | 12.6% |
| Age 55 to 59 | 7.7% | 5.5% | 6.7% |
| Age 60 to 64 | 9.8% | 4.6% | 6.3% |
| Age 65 to 74 | 11.2% | 9.4% | 9.6% |
| Age 75 to 84 | 3.3% | 2.3% | 4.5% |
| Age 85 and over | 1.7% | 0.7% | 1.9% |
| space1 | | | |
| Race | | | |
| | Mountain City, TX | Pearsall, TX | United States |
| White | 68.1% | 10.5% | 59.4% |
| Black | 0.0% | 3.1% | 12.2% |
| Asian | 1.3% | 1.4% | 5.6% |
| Native American | 0.2% | 0.1% | 0.6% |
| Hawaiian, Pacific Islander | 0.3% | 0.0% | 0.2% |
| Other | 0.0% | 0.0% | 0.4% |
| Two or More Races | 0.0% | 0.0% | 3.2% |
| Hispanic | 30.2% | 84.8% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Mountain City, TX | Pearsall, TX | United States |
| Married Population | 71.5% | 32.6% | 49.8% |
| Currently Married | 71.1% | 31.1% | 48.0% |
| Married but Separated | 0.4% | 1.6% | 1.8% |
| Single Population | 28.5% | 67.4% | 50.2% |
| Never Married | 16.3% | 50.3% | 33.8% |
| Divorced | 8.3% | 11.5% | 10.8% |
| Widowed | 3.9% | 5.6% | 5.6% |
| space5 | | | |
| Household Size | 3.00 | 3.47 | 2.60 |
| Households | 211 | 1,782 | 124,010,992 |
| Family Households | 180 | 1,370 | 80,755,759 |
| Married couple, w/children | 40.0% | 22.2% | 30.5% |
| Married couple, no children | 53.3% | 36.1% | 42.9% |
| Non Family Households | 31 | 412 | 43,255,233 |
| Single householder, w/children | 2.2% | 34.9% | 15.8% |
| Single householder, no children | 4.4% | 6.9% | 10.8% |