| Hard to Desert Hot Springs (California) | 5,899.63 mi (9,494.54 km) |
| Hard to DeSoto (Texas) | 5,279.49 mi (8,496.51 km) |
| Hard to Destin (Florida) | 4,968.86 mi (7,996.62 km) |
| Hard to Destrehan (Louisiana) | 5,152.86 mi (8,292.73 km) |
| Hard to Detroit (Michigan) | 4,269.80 mi (6,871.58 km) |
| Hard to Diamond Bar (California) | 5,936.62 mi (9,554.06 km) |
| Hard to Diamond Springs (California) | 5,749.84 mi (9,253.48 km) |
| Hard to Dickinson (North Dakota) | 4,753.80 mi (7,650.50 km) |
| Hard to Dickinson (Texas) | 5,369.93 mi (8,642.06 km) |
| Hard to Dickson (Tennessee) | 4,731.43 mi (7,614.50 km) |
| Hard to Difficult Run (Virginia) | 4,190.70 mi (6,744.28 km) |
| Hard to Dinuba (California) | 5,835.19 mi (9,390.83 km) |
| Hard to Discovery Bay (California) | 5,817.59 mi (9,362.50 km) |
| Hard to Dix Hills (New York) | 3,942.31 mi (6,344.53 km) |
| Hard to Dixon (California) | 5,791.71 mi (9,320.85 km) |
