| Keystone to Popovo | 5,755.57 mi (9,262.70 km) |
| Keystone to Provadia | 5,812.39 mi (9,354.14 km) |
| Keystone to Radnevo | 5,782.06 mi (9,305.33 km) |
| Keystone to Radomir | 5,643.63 mi (9,082.55 km) |
| Keystone to Rakitovo | 5,713.48 mi (9,194.96 km) |
| Keystone to Rakovski | 5,740.74 mi (9,238.83 km) |
| Keystone to Razgrad | 5,760.63 mi (9,270.84 km) |
| Keystone to Razlog | 5,690.04 mi (9,157.23 km) |
| Keystone to Ruse | 5,726.15 mi (9,215.34 km) |
| Keystone to Samokov | 5,677.66 mi (9,137.32 km) |
| Keystone to Sandanski | 5,693.19 mi (9,162.30 km) |
| Keystone to Sevlievo | 5,720.01 mi (9,205.47 km) |
| Keystone to Shumen | 5,787.58 mi (9,314.22 km) |
| Keystone to Silistra | 5,769.58 mi (9,285.23 km) |
| Keystone to Sliven | 5,784.83 mi (9,309.78 km) |
