Then distances from Lago Junín to several potential source points in the uppermost Mantaro river were measured, which enabled them to determine that the Cordillera Rumi Cruz was the most distant source of water in the Mantaro basin (and therefore in the entire Amazon basin).
The study focused on determining the origin of water in the Mantaro River system, specifically identifying the most distant source point. The findings indicated that the Cordillera Rumi Cruz was the farthest upstream source of water within both the Mantaro basin and the Amazon basin.