Migrants at a shelter in southern Mexico say that Mexico's interior checkpoints are making it harder to travel north. Some have given up on reaching the U.S. and are trying to stay in Mexico. Carrie Kahn/NPR hide caption

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A man looks out towards the US from the Mexican side of the border fence that divides the two countries in San Diego. The U.S. Border Patrol says it has seen about a 60 percent drop in the number of Central Americans apprehended at the border. Mark Ralston/AFP/Getty Images hide caption

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A motorcyclist drives past a mural of revolutionary heroes in Managua, Nicaragua. Most streets in the country don't have names. People give directions by using reference points, mostly Lake Managua, when in the capital. Carrie Kahn/NPR hide caption

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A family swims in Lake Nicaragua, which will encompass nearly half of the proposed canal's 172-mile route. Environmentalists worry that oil spills, pollution and dredging will destroy the country's largest supply of fresh water. Carrie Kahn/NPR hide caption

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Haley Nordeen, 19, is spending the entire summer at the Prodesenh center in San Mateo Milpas Altas, Guatemala. The American University student helped build the center's new library. Carrie Kahn/NPR hide caption

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Ezequiel Vazquez and his 15-year-old son, Ilbaro, leave a government-run shelter in Guatemala City. Ilbaro was deported from the U.S. after spending six months in a Texas detention facility. He returned with a U.S.- issued duffel bag full of clothes, shoes, books and toys. Carrie Kahn/NPR hide caption

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Amalia Diaz, a 22-year-old from Honduras, holds her 5-month-old daughter, Shilin, as they wait in Tequixquiac, Mexico, for a northbound train to pass. They plan to jump onboard and ride on top of the train all the way to the United States border. Carrie Kahn/NPR hide caption

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A migrant from El Salvador holds a map he received from church workers at the Mexico-Guatemala border. It shows the freight train schedules and routes to the U.S. border. Carrie Kahn/NPR hide caption

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