| Big Spring to Popovo | 6,258.20 mi (10,071.59 km) |
| Big Spring to Provadia | 6,306.88 mi (10,149.95 km) |
| Big Spring to Radnevo | 6,301.82 mi (10,141.80 km) |
| Big Spring to Radomir | 6,185.02 mi (9,953.83 km) |
| Big Spring to Rakitovo | 6,253.40 mi (10,063.88 km) |
| Big Spring to Rakovski | 6,268.96 mi (10,088.92 km) |
| Big Spring to Razgrad | 6,258.26 mi (10,071.70 km) |
| Big Spring to Razlog | 6,236.51 mi (10,036.69 km) |
| Big Spring to Ruse | 6,224.57 mi (10,017.47 km) |
| Big Spring to Samokov | 6,217.05 mi (10,005.38 km) |
| Big Spring to Sandanski | 6,245.59 mi (10,051.30 km) |
| Big Spring to Sevlievo | 6,236.71 mi (10,037.02 km) |
| Big Spring to Shumen | 6,285.07 mi (10,114.84 km) |
| Big Spring to Silistra | 6,252.66 mi (10,062.69 km) |
| Big Spring to Sliven | 6,295.82 mi (10,132.15 km) |
