| Boulder to Devnya | 5,976.48 mi (9,618.21 km) |
| Boulder to Dimitrovgrad | 5,985.48 mi (9,632.71 km) |
| Boulder to Dobrich | 5,963.99 mi (9,598.11 km) |
| Boulder to Dospat | 5,964.60 mi (9,599.10 km) |
| Boulder to Dupnitsa | 5,898.35 mi (9,492.47 km) |
| Boulder to Elhovo | 6,007.43 mi (9,668.02 km) |
| Boulder to Etropole | 5,893.76 mi (9,485.09 km) |
| Boulder to Gabrovo | 5,931.68 mi (9,546.11 km) |
| Boulder to Gorna Oryahovitsa | 5,927.46 mi (9,539.33 km) |
| Boulder to Gotse Delchev | 5,955.91 mi (9,585.12 km) |
| Boulder to Harmanli | 6,000.98 mi (9,657.64 km) |
| Boulder to Haskovo | 5,991.06 mi (9,641.68 km) |
| Boulder to Ihtiman | 5,910.17 mi (9,511.50 km) |
| Boulder to Isperih | 5,927.18 mi (9,538.87 km) |
| Boulder to Kardzhali | 6,001.00 mi (9,657.67 km) |
