 It is the longest river that runs entirely within the Central American isthmus.The river originates in the Somoto Canyon National Monument, near where the Pan American Highway crosses into Nicaragua, and flows through low mountainous terrain into the Caribbean Sea at Cabo Gracias a Dios; the middle and lower reaches form the Honduras-Nicaragua border.On September 7, 2007, major international news wires reported that the Río Coco was over above normal stage, two days after category 5 Hurricane Felix made landfall.