South America's Andes make up the longest mountain range in the world. From Venezuela in the north through the southern-most tip of Argentina, the range stretches about 5,000 miles. The Andes are part of the geological Ring of Fire, a ring of active volcanoes that border the Pacific Ocean. At 19,347 feet, Cotopaxi is the highest active volcano in the world. Over time, glaciers of melted ice and snow from the Andes have created rivers, including the...