| Northglenn to Popovo | 5,929.39 mi (9,542.43 km) |
| Northglenn to Provadia | 5,973.43 mi (9,613.30 km) |
| Northglenn to Radnevo | 5,979.70 mi (9,623.39 km) |
| Northglenn to Radomir | 5,875.41 mi (9,455.56 km) |
| Northglenn to Rakitovo | 5,941.56 mi (9,562.02 km) |
| Northglenn to Rakovski | 5,951.41 mi (9,577.87 km) |
| Northglenn to Razgrad | 5,927.26 mi (9,539.00 km) |
| Northglenn to Razlog | 5,928.08 mi (9,540.33 km) |
| Northglenn to Ruse | 5,894.65 mi (9,486.53 km) |
| Northglenn to Samokov | 5,905.79 mi (9,504.45 km) |
| Northglenn to Sandanski | 5,939.72 mi (9,559.06 km) |
| Northglenn to Sevlievo | 5,914.67 mi (9,518.74 km) |
| Northglenn to Shumen | 5,953.41 mi (9,581.08 km) |
| Northglenn to Silistra | 5,915.43 mi (9,519.97 km) |
| Northglenn to Sliven | 5,969.90 mi (9,607.63 km) |
