 The Bolsón has an endorheic or internal drainage system, meaning that no rivers leave the basin to flow to the sea, but terminate, often in shallow lakes, in low-lying areas.The Mapimí Mountains (Sierra de Mapimí) rise from the southern edge of the town of Mapimí, reaching a maximum elevation of , southeast of the town.The Ojuela mine and the Ojuela Bridge, a high and long suspension bridge are located distant on the eastern slopes of the mountains.