| Keystone to Devnya | 5,816.71 mi (9,361.09 km) |
| Keystone to Dimitrovgrad | 5,777.01 mi (9,297.19 km) |
| Keystone to Dobrich | 5,814.40 mi (9,357.37 km) |
| Keystone to Dospat | 5,729.22 mi (9,220.29 km) |
| Keystone to Dupnitsa | 5,661.12 mi (9,110.70 km) |
| Keystone to Elhovo | 5,814.27 mi (9,357.16 km) |
| Keystone to Etropole | 5,679.14 mi (9,139.70 km) |
| Keystone to Gabrovo | 5,735.28 mi (9,230.04 km) |
| Keystone to Gorna Oryahovitsa | 5,741.05 mi (9,239.34 km) |
| Keystone to Gotse Delchev | 5,713.16 mi (9,194.44 km) |
| Keystone to Harmanli | 5,794.33 mi (9,325.07 km) |
| Keystone to Haskovo | 5,779.90 mi (9,301.85 km) |
| Keystone to Ihtiman | 5,685.44 mi (9,149.84 km) |
| Keystone to Isperih | 5,766.98 mi (9,281.07 km) |
| Keystone to Kardzhali | 5,781.72 mi (9,304.78 km) |
