| Idaho Falls to Smolyan | 5,974.51 mi (9,615.04 km) |
| Idaho Falls to Sofia | 5,872.47 mi (9,450.83 km) |
| Idaho Falls to Sopot | 5,911.88 mi (9,514.26 km) |
| Idaho Falls to Sozopol | 5,998.69 mi (9,653.95 km) |
| Idaho Falls to Sredets | 5,990.70 mi (9,641.10 km) |
| Idaho Falls to Stamboliyski | 5,937.30 mi (9,555.16 km) |
| Idaho Falls to Stara Zagora | 5,947.53 mi (9,571.63 km) |
| Idaho Falls to Svilengrad | 6,001.49 mi (9,658.46 km) |
| Idaho Falls to Svishtov | 5,868.87 mi (9,445.04 km) |
| Idaho Falls to Targovishte | 5,921.14 mi (9,529.15 km) |
| Idaho Falls to Teteven | 5,883.66 mi (9,468.84 km) |
| Idaho Falls to Troyan | 5,897.07 mi (9,490.41 km) |
| Idaho Falls to Tryavna | 5,917.68 mi (9,523.59 km) |
| Idaho Falls to Tutrakan | 5,873.48 mi (9,452.46 km) |
| Idaho Falls to Varna | 5,955.01 mi (9,583.66 km) |
