| Clarksburg to Mangualde | 3,583.67 mi (5,767.35 km) |
| Clarksburg to Marco de Canavezes | 3,549.63 mi (5,712.58 km) |
| Clarksburg to Marinha Grande | 3,549.45 mi (5,712.29 km) |
| Clarksburg to Massama | 3,559.62 mi (5,728.65 km) |
| Clarksburg to Matosinhos | 3,523.12 mi (5,669.91 km) |
| Clarksburg to Mealhada | 3,556.13 mi (5,723.04 km) |
| Clarksburg to Melgaco | 3,520.15 mi (5,665.14 km) |
| Clarksburg to Melres | 3,540.61 mi (5,698.06 km) |
| Clarksburg to Mira | 3,541.04 mi (5,698.75 km) |
| Clarksburg to Miranda do Corvo | 3,569.36 mi (5,744.34 km) |
| Clarksburg to Mirandela | 3,588.25 mi (5,774.74 km) |
| Clarksburg to Mogadouro | 3,614.53 mi (5,817.03 km) |
| Clarksburg to Moimenta da Beira | 3,580.82 mi (5,762.77 km) |
| Clarksburg to Moita | 3,576.98 mi (5,756.59 km) |
| Clarksburg to Moncao | 3,511.06 mi (5,650.50 km) |
