| Difficult Run to Reidsville (North Carolina) | 218.11 mi (351.01 km) |
| Difficult Run to Reisterstown (Maryland) | 47.72 mi (76.80 km) |
| Difficult Run to Rendon (Texas) | 1,194.69 mi (1,922.67 km) |
| Difficult Run to Reno (Nevada) | 2,253.74 mi (3,627.04 km) |
| Difficult Run to Renton (Washington) | 2,301.09 mi (3,703.25 km) |
| Difficult Run to Republic (Missouri) | 883.35 mi (1,421.61 km) |
| Difficult Run to Reston (Virginia) | 3.32 mi (5.35 km) |
| Difficult Run to Revere (Massachusetts) | 411.62 mi (662.44 km) |
| Difficult Run to Rexburg (Idaho) | 1,804.75 mi (2,904.46 km) |
| Difficult Run to Reynoldsburg (Ohio) | 299.69 mi (482.30 km) |
| Difficult Run to Rialto (California) | 2,230.11 mi (3,589.02 km) |
| Difficult Run to Richardson (Texas) | 1,155.23 mi (1,859.17 km) |
| Difficult Run to Richfield (Minnesota) | 915.56 mi (1,473.46 km) |
| Difficult Run to Richfield (Wisconsin) | 640.98 mi (1,031.55 km) |
| Difficult Run to Richland (Washington) | 2,166.86 mi (3,487.22 km) |
