| Flagstaff to Popovo | 6,396.83 mi (10,294.71 km) |
| Flagstaff to Provadia | 6,439.27 mi (10,363.01 km) |
| Flagstaff to Radnevo | 6,449.02 mi (10,378.69 km) |
| Flagstaff to Radomir | 6,348.43 mi (10,216.81 km) |
| Flagstaff to Rakitovo | 6,413.84 mi (10,322.08 km) |
| Flagstaff to Rakovski | 6,422.11 mi (10,335.38 km) |
| Flagstaff to Razgrad | 6,394.02 mi (10,290.18 km) |
| Flagstaff to Razlog | 6,401.29 mi (10,301.88 km) |
| Flagstaff to Ruse | 6,361.85 mi (10,238.40 km) |
| Flagstaff to Samokov | 6,378.31 mi (10,264.89 km) |
| Flagstaff to Sandanski | 6,413.55 mi (10,321.61 km) |
| Flagstaff to Sevlievo | 6,384.18 mi (10,274.34 km) |
| Flagstaff to Shumen | 6,419.89 mi (10,331.81 km) |
| Flagstaff to Silistra | 6,380.21 mi (10,267.96 km) |
| Flagstaff to Sliven | 6,438.12 mi (10,361.15 km) |
