| | Canton, SD | Custer, SD | United States |
| Population | 3,054 | 2,067 | 329,725,481 |
| Female Population | 53.0% | 51.8% | 50.5% |
| Male Population | 47.0% | 48.2% | 49.5% |
| Median Age | 35.6 | 57.1 | 38.4 |
| space3 | | | |
| Population - 2010 | 3,102 | 2,015 | 309,327,143 |
| Population - 2000 | 3,110 | 1,860 | 285,036,114 |
| Population - 1990 | 2,787 | 1,741 | 251,960,433 |
| Pop. 2000 to Now | 15.2% | 3.6% | 15.6% |
| Pop. 1990 to Now | 28.6% | 10.6% | 30.8% |
| space4 | | | |
| Population Density | 940.9 | 817.0 | 93.4 |
| Land Area | 3.2 | 2.5 | 3,531,905.4 |
| Water Area | 0.0 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Canton, SD | Custer, SD | United States |
| Age 0 to 4 | 7.4% | 4.0% | 5.9% |
| Age 5 to 9 | 9.3% | 4.4% | 6.1% |
| Age 10 to 14 | 7.6% | 3.8% | 6.6% |
| Age 15 to 17 | 2.4% | 2.0% | 3.9% |
| Age 18 to 20 | 2.4% | 3.3% | 4.0% |
| Age 21 to 24 | 1.6% | 3.1% | 5.2% |
| Age 25 to 34 | 17.2% | 6.6% | 13.8% |
| Age 35 to 44 | 9.7% | 7.6% | 12.9% |
| Age 45 to 54 | 10.3% | 13.5% | 12.6% |
| Age 55 to 59 | 6.7% | 6.3% | 6.7% |
| Age 60 to 64 | 7.1% | 9.3% | 6.3% |
| Age 65 to 74 | 8.0% | 18.1% | 9.6% |
| Age 75 to 84 | 4.9% | 12.5% | 4.5% |
| Age 85 and over | 5.4% | 5.4% | 1.9% |
| space1 | | | |
| Race | | | |
| | Canton, SD | Custer, SD | United States |
| White | 93.5% | 86.5% | 59.4% |
| Black | 0.0% | 3.1% | 12.2% |
| Asian | 1.8% | 0.4% | 5.6% |
| Native American | 1.6% | 4.1% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 0.0% | 0.4% |
| Two or More Races | 2.8% | 1.1% | 3.2% |
| Hispanic | 0.3% | 4.8% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Canton, SD | Custer, SD | United States |
| Married Population | 49.7% | 54.4% | 49.8% |
| Currently Married | 49.1% | 54.4% | 48.0% |
| Married but Separated | 0.6% | 0.0% | 1.8% |
| Single Population | 50.3% | 45.6% | 50.2% |
| Never Married | 28.9% | 20.8% | 33.8% |
| Divorced | 13.5% | 16.3% | 10.8% |
| Widowed | 7.9% | 8.4% | 5.6% |
| space5 | | | |
| Household Size | 2.35 | 1.97 | 2.60 |
| Households | 1,177 | 977 | 124,010,992 |
| Family Households | 753 | 626 | 80,755,759 |
| Married couple, w/children | 37.1% | 13.9% | 30.5% |
| Married couple, no children | 38.4% | 64.1% | 42.9% |
| Non Family Households | 424 | 351 | 43,255,233 |
| Single householder, w/children | 18.9% | 13.9% | 15.8% |
| Single householder, no children | 5.7% | 8.1% | 10.8% |