9781422286920

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For more than 1,000 miles (1,600 km) the Río Grande marks the northern border of Mexico. Here, the river flows between the Mexican state of Coahuila and the U.S. state of Texas.

The Land I magine Mexico as a giant letter “vee” with its the top opening toward the United States. Two rugged mountain ranges form the edges of the vee— the “Mother” mountains: the Sierra Madre Oriental and the Sierra Madre Occidental. In the north, they are wide apart, separated by the Meseta Central (the Central Plateau ). The northern states of Mexico lie within the top of this vee. This region is composed of seven states: Chihuahua, Coahuila, Durango, Nuevo León, San Luis Potosí, Tamaulipas, and Zacatecas. When you look at a map of Mexico it is difficult to tell which areas are tierra caliente, tierra templada , or tierra fría —the hot-, medium-, and cold-weather areas. This is because the climate in Mexico is determined not by whether the land is in the north or the south as much as by elevation—the higher up in the mountains, the cooler the region. Much of this area falls into the medium- weather or temperate zone. The state of Tamaulipas, which lies along the Gulf Coast, however, is tierra caliente , as is the northernmost part of the land that slopes down toward the Río Grande. The northern edge of this area lies along the Río Grande, the river that marks about 1,000 miles (1,600 km) of the border between Mexico and the

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