- Located along MO 30 southeast of Eureka
- Latitude: 38°26'16" N (+38.4378)
- Longitude: 90°34'54" W (-90.5817)
- Elevation: 458 feet above sea level
- Civil township: High Ridge
- Land area: 5.0 square miles
- Water area: 0.14 square miles (87.5 acres)
As the crow flies, Byrnes Mill is...
| Year | Population | Percent change |
|---|
| 1990 | 1,578 | -- |
| 2000 | 2,376 | +50.6% |