In April 2017, a landslide in Mocoa, Colombia, ripped through a local town, killing more than 300 people. Nicolás Pérez-Consuegra grew up about 570 miles north in Santander, Colombia, and was shocked as he watched the devastation on television. At that time, he was an undergraduate intern at the Smithsonian Tropical Research Institute in Panama. As a budding geologist raised hiking the tropical mountains of Colombia, he wondered, what causes greater erosion in some areas of the mountains than in others? And, is it tectonic forces—where Earth's tectonic plates slide against one another leading to the formation of steep mountains—or high precipitation rates, that play a more important role in causing erosion within that region?