| Harker Heights to Smolyan | 6,220.04 mi (10,010.19 km) |
| Harker Heights to Sofia | 6,116.07 mi (9,842.86 km) |
| Harker Heights to Sopot | 6,171.02 mi (9,931.30 km) |
| Harker Heights to Sozopol | 6,289.17 mi (10,121.45 km) |
| Harker Heights to Sredets | 6,274.57 mi (10,097.95 km) |
| Harker Heights to Stamboliyski | 6,187.63 mi (9,958.03 km) |
| Harker Heights to Stara Zagora | 6,214.39 mi (10,001.10 km) |
| Harker Heights to Svilengrad | 6,266.77 mi (10,085.40 km) |
| Harker Heights to Svishtov | 6,146.55 mi (9,891.92 km) |
| Harker Heights to Targovishte | 6,208.45 mi (9,991.54 km) |
| Harker Heights to Teteven | 6,140.56 mi (9,882.28 km) |
| Harker Heights to Troyan | 6,158.67 mi (9,911.42 km) |
| Harker Heights to Tryavna | 6,188.03 mi (9,958.68 km) |
| Harker Heights to Tutrakan | 6,170.61 mi (9,930.63 km) |
| Harker Heights to Varna | 6,257.25 mi (10,070.07 km) |
