| Difficult Run to Bixby (Oklahoma) | 1,035.19 mi (1,665.98 km) |
| Difficult Run to Black Forest (Colorado) | 1,462.25 mi (2,353.27 km) |
| Difficult Run to Blackfoot (Idaho) | 1,833.94 mi (2,951.45 km) |
| Difficult Run to Blackhawk (California) | 2,391.03 mi (3,847.99 km) |
| Difficult Run to Blacksburg (Virginia) | 203.51 mi (327.52 km) |
| Difficult Run to Blackwells Mills (New Jersey) | 182.26 mi (293.31 km) |
| Difficult Run to Blaine (Minnesota) | 919.71 mi (1,480.12 km) |
| Difficult Run to Bloomingdale (Florida) | 812.34 mi (1,307.34 km) |
| Difficult Run to Bloomingdale (Illinois) | 602.47 mi (969.58 km) |
| Difficult Run to Bloomington (California) | 2,232.15 mi (3,592.29 km) |
| Difficult Run to Bloomington (Illinois) | 627.01 mi (1,009.07 km) |
| Difficult Run to Bloomington (Indiana) | 492.75 mi (793.00 km) |
| Difficult Run to Bloomington (Minnesota) | 915.90 mi (1,474.00 km) |
| Difficult Run to Bloomsburg (Pennsylvania) | 152.65 mi (245.66 km) |
| Difficult Run to Blue Ash (Ohio) | 378.04 mi (608.40 km) |
