| Griffin to Mangualde | 4,123.37 mi (6,635.92 km) |
| Griffin to Marco de Canavezes | 4,090.96 mi (6,583.77 km) |
| Griffin to Marinha Grande | 4,084.77 mi (6,573.80 km) |
| Griffin to Massama | 4,090.67 mi (6,583.29 km) |
| Griffin to Matosinhos | 4,063.91 mi (6,540.23 km) |
| Griffin to Mealhada | 4,094.33 mi (6,589.18 km) |
| Griffin to Melgaco | 4,064.52 mi (6,541.21 km) |
| Griffin to Melres | 4,081.29 mi (6,568.20 km) |
| Griffin to Mira | 4,079.12 mi (6,564.70 km) |
| Griffin to Miranda do Corvo | 4,106.65 mi (6,609.02 km) |
| Griffin to Mirandela | 4,131.53 mi (6,649.05 km) |
| Griffin to Mogadouro | 4,157.75 mi (6,691.25 km) |
| Griffin to Moimenta da Beira | 4,121.98 mi (6,633.68 km) |
| Griffin to Moita | 4,107.96 mi (6,611.12 km) |
| Griffin to Moncao | 4,055.09 mi (6,526.03 km) |
