| South Sioux City to Karlovo | 5,517.70 mi (8,879.88 km) |
| South Sioux City to Karnobat | 5,588.20 mi (8,993.34 km) |
| South Sioux City to Kavarna | 5,586.98 mi (8,991.38 km) |
| South Sioux City to Kazanlak | 5,538.38 mi (8,913.15 km) |
| South Sioux City to Knezha | 5,448.91 mi (8,769.17 km) |
| South Sioux City to Kostinbrod | 5,456.35 mi (8,781.14 km) |
| South Sioux City to Kozloduy | 5,422.66 mi (8,726.93 km) |
| South Sioux City to Kyustendil | 5,466.42 mi (8,797.35 km) |
| South Sioux City to Levski | 5,489.87 mi (8,835.09 km) |
| South Sioux City to Lom | 5,404.30 mi (8,697.38 km) |
| South Sioux City to Lovech | 5,488.75 mi (8,833.29 km) |
| South Sioux City to Lukovit | 5,467.42 mi (8,798.97 km) |
| South Sioux City to Lyaskovets | 5,522.78 mi (8,888.06 km) |
| South Sioux City to Mezdra | 5,454.80 mi (8,778.66 km) |
| South Sioux City to Momchilgrad | 5,596.72 mi (9,007.05 km) |
