Covering almost two million square kilometres (over 760,000 sq mi), Mexico is the fifth largest country in the Americas by total area and the 13th largest independent nation in the world. With an estimated population of over 120 million, it is the eleventh most populous and the most populous Spanish-speaking country in the world and the second most populous country in Latin America. Mexico is a federation comprising thirty-one states and a Federal District, its capital and largest city.
Mexico is located in the southern portion of North America. Almost all of Mexico lies in the North American Plate, with small parts of the Baja California peninsula on the Pacific and Cocos Plates. Geophysically, some geographers include the territory east of the Isthmus of Tehuantepec (around 12% of the total) within Central America. Geopolitically, however, Mexico is entirely considered part of North America, along with Canada and the United States.
Mexico is crossed from north to south by two mountain ranges known as Sierra Madre Oriental and Sierra Madre Occidental, which are the extension of the Rocky Mountains from northern North America. From east to west at the center, the country is crossed by the Trans-Mexican Volcanic Belt also known as the Sierra Nevada. A fourth mountain range, the Sierra Madre del Sur, runs from Michoacán to Oaxaca.
As such, the majority of the Mexican central and northern territories are located at high altitudes, and the highest elevations are found at the Trans-Mexican Volcanic Belt: Pico de Orizaba (5,700 m or 18,701 ft), Popocatepetl (5,462 m or 17,920 ft) and Iztaccihuatl (5,286 m or 17,343 ft) and the Nevado de Toluca (4,577 m or 15,016 ft). Three major urban agglomerations are located in the valleys between these four elevations: Toluca, Greater Mexico City and Puebla.
The Tropic of Cancer effectively divides the country into temperate and tropical zones. Land north of the twenty-fourth parallel experiences cooler temperatures during the winter months. South of the twenty-fourth parallel, temperatures are fairly constant year round and vary solely as a function of elevation. This gives Mexico one of the world’s most diverse weather systems.
Mexico is one of the 18 megadiverse countries of the world. With over 200,000 different species, Mexico is home of 10–12% of the world’s biodiversity. Mexico ranks first in biodiversity in reptiles with 707 known species, second in mammals with 438 species, fourth in amphibians with 290 species, and fourth in flora, with 26,000 different species. Mexico is also considered the second country in the world in ecosystems and fourth in overall species. Approximately 2,500 species are protected by Mexican legislations.
In Mexico, 170,000 square kilometres (65,637 sq mi) are considered “Protected Natural Areas.” These include 34 biosphere reserves (unaltered ecosystems), 67 national parks, 4 natural monuments (protected in perpetuity for their aesthetic, scientific or historical value), 26 areas of protected flora and fauna, 4 areas for natural resource protection (conservation of soil, hydrological basins and forests) and 17 sanctuaries (zones rich in diverse species).
The Monarch Butterfly Biosphere Reserve is a World Heritage Site containing most of the over-wintering sites of the eastern population of the monarch butterfly. The reserve is located in the Trans-Mexican Volcanic Belt pine-oak forests ecoregion on the border of Michoacán and Mexico State, 100 km (62 miles), northwest of Mexico City. Millions of butterflies arrive in the preserve annually. Butterflies only inhabit a fraction of the 56,000 hectares of the reserve from October–March. The biosphere’s mission is to protect the butterfly species and its habitat.