| Prairie Ridge to Smolyan | 5,978.21 mi (9,621.01 km) |
| Prairie Ridge to Sofia | 5,880.18 mi (9,463.24 km) |
| Prairie Ridge to Sopot | 5,910.78 mi (9,512.48 km) |
| Prairie Ridge to Sozopol | 5,979.53 mi (9,623.13 km) |
| Prairie Ridge to Sredets | 5,975.06 mi (9,615.92 km) |
| Prairie Ridge to Stamboliyski | 5,939.76 mi (9,559.12 km) |
| Prairie Ridge to Stara Zagora | 5,941.56 mi (9,562.02 km) |
| Prairie Ridge to Svilengrad | 5,994.69 mi (9,647.51 km) |
| Prairie Ridge to Svishtov | 5,859.91 mi (9,430.61 km) |
| Prairie Ridge to Targovishte | 5,905.86 mi (9,504.56 km) |
| Prairie Ridge to Teteven | 5,884.50 mi (9,470.19 km) |
| Prairie Ridge to Troyan | 5,895.19 mi (9,487.39 km) |
| Prairie Ridge to Tryavna | 5,910.88 mi (9,512.65 km) |
| Prairie Ridge to Tutrakan | 5,854.76 mi (9,422.32 km) |
| Prairie Ridge to Varna | 5,931.33 mi (9,545.55 km) |
