| | Junction City, OR | Harrisburg, OR | United States |
| Population | 6,718 | 3,645 | 329,725,481 |
| Female Population | 51.2% | 50.7% | 50.5% |
| Male Population | 48.9% | 49.3% | 49.5% |
| Median Age | 37.6 | 35.8 | 38.4 |
| space3 | | | |
| Population - 2010 | 5,369 | 3,573 | 309,327,143 |
| Population - 2000 | 4,721 | 2,795 | 285,036,114 |
| Population - 1990 | 3,670 | 1,939 | 251,960,433 |
| Pop. 2000 to Now | 31.6% | 40.1% | 15.6% |
| Pop. 1990 to Now | 69.2% | 102.0% | 30.8% |
| space4 | | | |
| Population Density | 2,047.6 | 2,612.9 | 93.4 |
| Land Area | 3.3 | 1.4 | 3,531,905.4 |
| Water Area | 0.0 | 0.1 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Junction City, OR | Harrisburg, OR | United States |
| Age 0 to 4 | 5.2% | 9.0% | 5.9% |
| Age 5 to 9 | 7.6% | 11.4% | 6.1% |
| Age 10 to 14 | 6.8% | 7.4% | 6.6% |
| Age 15 to 17 | 3.1% | 3.3% | 3.9% |
| Age 18 to 20 | 3.6% | 0.5% | 4.0% |
| Age 21 to 24 | 3.2% | 2.5% | 5.2% |
| Age 25 to 34 | 18.2% | 15.3% | 13.8% |
| Age 35 to 44 | 14.3% | 19.8% | 12.9% |
| Age 45 to 54 | 9.2% | 7.1% | 12.6% |
| Age 55 to 59 | 5.6% | 3.7% | 6.7% |
| Age 60 to 64 | 5.7% | 10.8% | 6.3% |
| Age 65 to 74 | 8.9% | 5.7% | 9.6% |
| Age 75 to 84 | 7.7% | 1.9% | 4.5% |
| Age 85 and over | 1.1% | 1.7% | 1.9% |
| space1 | | | |
| Race | | | |
| | Junction City, OR | Harrisburg, OR | United States |
| White | 84.9% | 89.5% | 59.4% |
| Black | 0.3% | 0.3% | 12.2% |
| Asian | 0.0% | 0.0% | 5.6% |
| Native American | 0.1% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 0.0% | 0.4% |
| Two or More Races | 4.9% | 8.9% | 3.2% |
| Hispanic | 9.8% | 1.2% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Junction City, OR | Harrisburg, OR | United States |
| Married Population | 47.5% | 56.6% | 49.8% |
| Currently Married | 47.5% | 53.8% | 48.0% |
| Married but Separated | 0.0% | 2.8% | 1.8% |
| Single Population | 52.5% | 43.4% | 50.2% |
| Never Married | 31.1% | 23.3% | 33.8% |
| Divorced | 16.2% | 16.2% | 10.8% |
| Widowed | 5.2% | 4.0% | 5.6% |
| space5 | | | |
| Household Size | 2.42 | 2.66 | 2.60 |
| Households | 2,726 | 1,369 | 124,010,992 |
| Family Households | 1,772 | 937 | 80,755,759 |
| Married couple, w/children | 28.9% | 43.0% | 30.5% |
| Married couple, no children | 36.9% | 24.3% | 42.9% |
| Non Family Households | 954 | 432 | 43,255,233 |
| Single householder, w/children | 12.6% | 23.4% | 15.8% |
| Single householder, no children | 21.6% | 9.3% | 10.8% |