Anyier sits at the side of the road gasping for breath as the beating sun and 3,700-meter (12,000-foot) altitude take their toll. It has been seven hours since she entered Chile from Bolivia on foot — her fifth border crossing since leaving Venezuela nearly a month and 5,000 kilometers (more than 3,000 miles) ago. “This has been the toughest,” she pants, sunburned and with chapped lips. “Awful.” The 40-year-old, a former employee of Venezuela’s national iron and steel company, set off for Chile on January 25 with her 14-year-old daughter Dany and her partner, 26-year-old barber Reinaldo. They left a Caracas suburb with just $350 and a backpack of bare essentials for the long walk across the Andean high plane and the Atacama desert, crossing Colombia, Ecuador, Peru and Bolivia. They were not alone. In small groups, exhausted migrants advance slowly, mainly on foot, completing portions of the journey by bus or taxi, some catching rides on the roofs of delivery trucks.