| Casper to Smolyan | 5,856.30 mi (9,424.80 km) |
| Casper to Sofia | 5,753.03 mi (9,258.61 km) |
| Casper to Sopot | 5,796.45 mi (9,328.48 km) |
| Casper to Sozopol | 5,891.48 mi (9,481.42 km) |
| Casper to Sredets | 5,881.82 mi (9,465.88 km) |
| Casper to Stamboliyski | 5,819.95 mi (9,366.30 km) |
| Casper to Stara Zagora | 5,834.22 mi (9,389.26 km) |
| Casper to Svilengrad | 5,888.20 mi (9,476.14 km) |
| Casper to Svishtov | 5,757.58 mi (9,265.93 km) |
| Casper to Targovishte | 5,812.58 mi (9,354.44 km) |
| Casper to Teteven | 5,767.48 mi (9,281.86 km) |
| Casper to Troyan | 5,782.11 mi (9,305.41 km) |
| Casper to Tryavna | 5,804.99 mi (9,342.22 km) |
| Casper to Tutrakan | 5,766.96 mi (9,281.02 km) |
| Casper to Varna | 5,850.35 mi (9,415.23 km) |
