AdvertisementA once-remote patch of rainforest is now packed with migrants trying to reach the U.S.November 19, 2021John OtisfacebookEmailColombian guides and migrants walk and ride motorcycles at the beginning of the journey through the Darién Gap. To cover the first few miles, migrants can pay to ride on the back of motorcycles that navigate muddy trails. But soon the jungle thickens, and they must start walking. (Carlos Villalón for NPR)