| Riverdale to Popovo | 5,558.62 mi (8,945.73 km) |
| Riverdale to Provadia | 5,613.22 mi (9,033.61 km) |
| Riverdale to Radnevo | 5,590.98 mi (8,997.81 km) |
| Riverdale to Radomir | 5,458.80 mi (8,785.08 km) |
| Riverdale to Rakitovo | 5,528.68 mi (8,897.55 km) |
| Riverdale to Rakovski | 5,552.18 mi (8,935.37 km) |
| Riverdale to Razgrad | 5,562.08 mi (8,951.30 km) |
| Riverdale to Razlog | 5,507.30 mi (8,863.14 km) |
| Riverdale to Ruse | 5,527.58 mi (8,895.79 km) |
| Riverdale to Samokov | 5,492.40 mi (8,839.17 km) |
| Riverdale to Sandanski | 5,512.51 mi (8,871.53 km) |
| Riverdale to Sevlievo | 5,527.43 mi (8,895.54 km) |
| Riverdale to Shumen | 5,589.19 mi (8,994.94 km) |
| Riverdale to Silistra | 5,566.38 mi (8,958.22 km) |
| Riverdale to Sliven | 5,590.85 mi (8,997.61 km) |
