| Difficult Run to Kinston (North Carolina) | 250.96 mi (403.89 km) |
| Difficult Run to Kirkland (Washington) | 2,301.29 mi (3,703.57 km) |
| Difficult Run to Kirksville (Missouri) | 815.20 mi (1,311.94 km) |
| Difficult Run to Kirkwood (Missouri) | 704.29 mi (1,133.45 km) |
| Difficult Run to Kiryas Joel (New York) | 237.97 mi (382.97 km) |
| Difficult Run to Kissimmee (Florida) | 768.52 mi (1,236.81 km) |
| Difficult Run to Klamath Falls (Oregon) | 2,316.92 mi (3,728.73 km) |
| Difficult Run to Knightdale (North Carolina) | 223.99 mi (360.48 km) |
| Difficult Run to Knik-Fairview (Alaska) | 3,338.79 mi (5,373.27 km) |
| Difficult Run to Knoxville (Tennessee) | 414.88 mi (667.69 km) |
| Difficult Run to Kokomo (Indiana) | 478.99 mi (770.86 km) |
| Difficult Run to Kuna (Idaho) | 2,035.61 mi (3,276.00 km) |
| Difficult Run to Kyle (Texas) | 1,317.89 mi (2,120.95 km) |
| Difficult Run to La Cañada Flintridge (California) | 2,271.38 mi (3,655.43 km) |
| Difficult Run to La Crescenta-Montrose (California) | 2,272.72 mi (3,657.59 km) |
