| Richardson to Smolyan | 6,083.08 mi (9,789.78 km) |
| Richardson to Sofia | 5,979.03 mi (9,622.31 km) |
| Richardson to Sopot | 6,033.50 mi (9,709.98 km) |
| Richardson to Sozopol | 6,150.74 mi (9,898.66 km) |
| Richardson to Sredets | 6,136.34 mi (9,875.48 km) |
| Richardson to Stamboliyski | 6,050.45 mi (9,737.25 km) |
| Richardson to Stara Zagora | 6,076.66 mi (9,779.43 km) |
| Richardson to Svilengrad | 6,129.17 mi (9,863.94 km) |
| Richardson to Svishtov | 6,008.36 mi (9,669.51 km) |
| Richardson to Targovishte | 6,070.02 mi (9,768.75 km) |
| Richardson to Teteven | 6,003.07 mi (9,661.01 km) |
| Richardson to Troyan | 6,021.04 mi (9,689.94 km) |
| Richardson to Tryavna | 6,050.14 mi (9,736.76 km) |
| Richardson to Tutrakan | 6,031.81 mi (9,707.26 km) |
| Richardson to Varna | 6,118.40 mi (9,846.61 km) |
