- Located near US 63 crossing of Black River northwest of Walnut Ridge
- Latitude: 36°06'30" N (+36.1083)
- Longitude: 91°05'50" W (-91.0972)
- Elevation: 300 feet above sea level
- Civil township: Black Rock
- Land area: 3.3 square miles
- Water area: 0.15 square miles (96.3 acres)
As the crow flies, Black Rock is...
| Year | Population | Percent change |
|---|
| 1890 | 761 | -- |
| 1900 | 1,400 | +84.0% |
| 1910 | 1,078 | -23.0% |
| 1920 | 835 | -22.5% |
| 1930 | 751 | -10.1% |
| 1940 | 769 | +2.4% |
| 1950 | 662 | -13.9% |
| 1960 | 554 | -16.3% |
| 1970 | 498 | -10.1% |
| 1980 | 848 | +70.3% |
| 1990 | 736 | -13.2% |
| 2000 | 717 | -2.6% |