Mexican Federal Highway 40, also called the Carretera Interoceánica and colloquially known as the "Fed 40", is a major east–west highway that spans more than 1,140 kilometres (700 mi) through northern Mexico, beginning at Reynosa, Tamaulipas, and ending at its intersection with Mexican Federal Highway 15 in Villa Unión, Sinaloa, near Mazatlán and the Pacific coast. It is called "interoceanic" because the cities of Matamoros, Tamaulipas, on the Gulf of Mexico and Mazatlán on the Pacific Ocean were linked upon its opening.