| Casper to Popovo | 5,797.24 mi (9,329.75 km) |
| Casper to Provadia | 5,839.41 mi (9,397.62 km) |
| Casper to Radnevo | 5,849.83 mi (9,414.39 km) |
| Casper to Radomir | 5,750.54 mi (9,254.59 km) |
| Casper to Rakitovo | 5,815.63 mi (9,359.35 km) |
| Casper to Rakovski | 5,823.33 mi (9,371.74 km) |
| Casper to Razgrad | 5,794.30 mi (9,325.02 km) |
| Casper to Razlog | 5,803.46 mi (9,339.77 km) |
| Casper to Ruse | 5,762.21 mi (9,273.37 km) |
| Casper to Samokov | 5,780.19 mi (9,302.32 km) |
| Casper to Sandanski | 5,816.00 mi (9,359.95 km) |
| Casper to Sevlievo | 5,785.06 mi (9,310.15 km) |
| Casper to Shumen | 5,820.12 mi (9,366.57 km) |
| Casper to Silistra | 5,780.22 mi (9,302.36 km) |
| Casper to Sliven | 5,838.67 mi (9,396.44 km) |
