| Big Spring to Smolyan | 6,295.31 mi (10,131.32 km) |
| Big Spring to Sofia | 6,191.03 mi (9,963.50 km) |
| Big Spring to Sopot | 6,243.19 mi (10,047.45 km) |
| Big Spring to Sozopol | 6,355.69 mi (10,228.50 km) |
| Big Spring to Sredets | 6,342.36 mi (10,207.04 km) |
| Big Spring to Stamboliyski | 6,261.71 mi (10,077.24 km) |
| Big Spring to Stara Zagora | 6,285.27 mi (10,115.17 km) |
| Big Spring to Svilengrad | 6,338.33 mi (10,200.55 km) |
| Big Spring to Svishtov | 6,214.76 mi (10,001.69 km) |
| Big Spring to Targovishte | 6,275.09 mi (10,098.78 km) |
| Big Spring to Teteven | 6,212.98 mi (9,998.83 km) |
| Big Spring to Troyan | 6,230.26 mi (10,026.63 km) |
| Big Spring to Tryavna | 6,258.03 mi (10,071.32 km) |
| Big Spring to Tutrakan | 6,234.96 mi (10,034.20 km) |
| Big Spring to Varna | 6,321.12 mi (10,172.85 km) |
