Why Is Chile So Long and Skinny?

Natural boundaries and military conquest.


The magnitude-8.8 earthquake that struck off the coast of Chile on Saturday was just one of more than a dozen catastrophic quakes to strike the country in the last half-century. Seismologists blame Chile’s serpentine, 4,000-mile Pacific border, which runs directly astride the convergent boundary of the Nazca and South American plates. How did Chile get to be so long and skinny, anyway?

Natural boundaries and military conquests. Chile has had its current shape since the late 1880s, when the nation finally captured its southern territories. Its meager width and impressive length have differing origins, however. The former is determined by the local geography: The country is wedged between the Andes mountain range to the east and the Pacific Ocean to the west. As such, it measures an average of only 109 miles across, but even that understates how narrow the country really is. The mountains that run along the border with Argentina occupy between one-third and one-half of Chile’s width. Most Chileans live in the country’s fertile Central Valley, a narrow ribbon of habitable land that runs alongside a smaller range of mountains on the coast.

Chile’s length is largely a product of colonial expansion and modern military campaigns. In the 16th century, a contingent of conquistadors migrated into the area from the Peruvian colony, in search of gold. They settled near present-day Santiago, with some more outposts farther south. The Andes, which are the highest mountain range in the Western Hemisphere, discouraged the Spaniards from extending their colony to the east.

When Chile won its independence from Spain in 1818, the country comprised the middle one-third of what it is today. It was not until the late 19th century that the nation acquired most of its land. During the War of the Pacific in the 1880s, Chile battled Peru and Bolivia for control of the lucrative, nitrate-rich land to the north. The victorious Chileans snatched up Peru’s southern tip and Bolivia’s entire Pacific coast. (Bolivia has been landlocked ever since.)

Chile conquered the bottom one-third of the country around the same time, amassing the long strip of land below the Biobío River that belonged for centuries to an indigenous people known as the Mapuche. Although this group successfully resisted subjugation by both the Incan and Spanish empires, the Mapuche were finally defeated by the Chilean army in the 1880s.

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Explainer thanks Florencia Mallon of the University of Wisconsin-Madison, and Nara Milanich and José Moya of Barnard College.

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