| Houston to Devnya | 6,233.84 mi (10,032.40 km) |
| Houston to Dimitrovgrad | 6,214.79 mi (10,001.74 km) |
| Houston to Dobrich | 6,226.97 mi (10,021.34 km) |
| Houston to Dospat | 6,177.79 mi (9,942.20 km) |
| Houston to Dupnitsa | 6,109.25 mi (9,831.89 km) |
| Houston to Elhovo | 6,246.05 mi (10,052.05 km) |
| Houston to Etropole | 6,117.81 mi (9,845.66 km) |
| Houston to Gabrovo | 6,167.03 mi (9,924.87 km) |
| Houston to Gorna Oryahovitsa | 6,168.53 mi (9,927.29 km) |
| Houston to Gotse Delchev | 6,164.62 mi (9,920.99 km) |
| Houston to Harmanli | 6,231.63 mi (10,028.85 km) |
| Houston to Haskovo | 6,218.91 mi (10,008.36 km) |
| Houston to Ihtiman | 6,128.61 mi (9,863.05 km) |
| Houston to Isperih | 6,183.38 mi (9,951.19 km) |
| Houston to Kardzhali | 6,224.29 mi (10,017.02 km) |
