| Box Elder to Smolyan | 5,690.48 mi (9,157.94 km) |
| Box Elder to Sofia | 5,586.94 mi (8,991.31 km) |
| Box Elder to Sopot | 5,631.54 mi (9,063.09 km) |
| Box Elder to Sozopol | 5,729.10 mi (9,220.09 km) |
| Box Elder to Sredets | 5,718.91 mi (9,203.70 km) |
| Box Elder to Stamboliyski | 5,654.43 mi (9,099.92 km) |
| Box Elder to Stara Zagora | 5,669.94 mi (9,124.88 km) |
| Box Elder to Svilengrad | 5,723.88 mi (9,211.69 km) |
| Box Elder to Svishtov | 5,594.01 mi (9,002.70 km) |
| Box Elder to Targovishte | 5,649.84 mi (9,092.53 km) |
| Box Elder to Teteven | 5,602.37 mi (9,016.14 km) |
| Box Elder to Troyan | 5,617.37 mi (9,040.28 km) |
| Box Elder to Tryavna | 5,640.93 mi (9,078.20 km) |
| Box Elder to Tutrakan | 5,604.93 mi (9,020.26 km) |
| Box Elder to Varna | 5,688.85 mi (9,155.31 km) |
