| Difficult Run to Bonham (Texas) | 1,109.83 mi (1,786.10 km) |
| Difficult Run to Bonita (California) | 2,247.43 mi (3,616.89 km) |
| Difficult Run to Bonita Springs (Florida) | 904.16 mi (1,455.10 km) |
| Difficult Run to Bonney Lake (Washington) | 2,300.82 mi (3,702.81 km) |
| Difficult Run to Boone (Iowa) | 894.05 mi (1,438.84 km) |
| Difficult Run to Boone (North Carolina) | 300.84 mi (484.15 km) |
| Difficult Run to Borger (Texas) | 1,337.21 mi (2,152.02 km) |
| Difficult Run to Bossier City (Louisiana) | 1,014.08 mi (1,632.00 km) |
| Difficult Run to Boston (Massachusetts) | 404.33 mi (650.70 km) |
| Difficult Run to Bostonia (California) | 2,239.00 mi (3,603.33 km) |
| Difficult Run to Bothell (Washington) | 2,301.09 mi (3,703.25 km) |
| Difficult Run to Bothell East (Washington) | 2,300.11 mi (3,701.67 km) |
| Difficult Run to Bothell West (Washington) | 2,302.70 mi (3,705.83 km) |
| Difficult Run to Boulder (Colorado) | 1,484.47 mi (2,389.02 km) |
| Difficult Run to Boulder City (Nevada) | 2,059.67 mi (3,314.71 km) |
