| Williamsport to Popovo | 4,899.62 mi (7,885.17 km) |
| Williamsport to Provadia | 4,953.48 mi (7,971.86 km) |
| Williamsport to Radnevo | 4,933.81 mi (7,940.20 km) |
| Williamsport to Radomir | 4,804.08 mi (7,731.41 km) |
| Williamsport to Rakitovo | 4,873.83 mi (7,843.68 km) |
| Williamsport to Rakovski | 4,895.94 mi (7,879.25 km) |
| Williamsport to Razgrad | 4,902.60 mi (7,889.97 km) |
| Williamsport to Razlog | 4,853.27 mi (7,810.59 km) |
| Williamsport to Ruse | 4,868.15 mi (7,834.52 km) |
| Williamsport to Samokov | 4,837.46 mi (7,785.14 km) |
| Williamsport to Sandanski | 4,859.28 mi (7,820.25 km) |
| Williamsport to Sevlievo | 4,869.87 mi (7,837.29 km) |
| Williamsport to Shumen | 4,929.72 mi (7,933.62 km) |
| Williamsport to Silistra | 4,905.58 mi (7,894.77 km) |
| Williamsport to Sliven | 4,932.73 mi (7,938.47 km) |
