Sierra Negra

Sierra Negra

The curvy and hairpinned mountainous road up to Sierra Negra (also called Cerro La Negra) is claimed to be the highest road in North America. This Mexican dirt track climbs up to 4.640m (15,220ft) above the sea level. At the top of the climb you will find the biggest Millimetric RadioTelescope in the world. It’s one of the famous hairpinned roads in the world

The Large Millimeter Telescope located on the top of this volcano, called Sierra Negra, Tliltépetl or volcán Atlitzin  is the world´s largest single-dish steerable millimetre-wavelength telescope designed specifically for astronomical observations in the wavelength range of 0.85 – 4mm. It’s one of the highest mountain roads of the country.
The access goes through La Esperanza Town, near the freeway from Puebla to Veracruz. Starting from this point, the ascent is 19.9 km long. Over this distance, the elevation gain is 1.880 meters. The average percentage is 9.4 %. The road is located between the states of Veracruz and Puebla. With such a high summit altitude the road can be closed anytime due to snowfalls. The zone is prone to heavy mist and can be dangerous in low visibility conditions.

Do not travel this pass in severe weather conditions. Avalanches, heavy snowfalls and landslides can occur anytime, being extremely dangerous due to frequent patches of ice. It has a well-deserved reputation for being dangerous because of unpredictable snowstorms and blizzards, and driving under these conditions, can be extremely challenging. There's a pedestrian trail next to this road, that goes to Pico de Orizaba (Citlaltépetl). The trail continues up to a small house located at 4.730 m above the sea level and then disappears, but many people continue hiking to the top of the mountain. At 5.747 m above sea level, it's Mexico highest mountain. 
Pic: jean gamboa