Laguna del Desierto incident Laguna del Desierto region, the tribunal set the "hito 62" (cornerstone 62) at the O'Higgins/San Martin Lake and draw the boundary from there to mount Fitz Roy on the Martínez de Rozas Range awarding Chile the complete valley of Laguna del Desierto. In 1946 an aerial reconnaissance of the United States Air Force, ordered by the Chilean government, revealed that the lake emptied to the Atlantic shores. Chile and Argentina have to redraw its maps. The initially organized labour support for 1963 elected Argentine President Arturo Illia turned to antagonism during 1964, as secret plans for Juan Domingo Perón's return
Laguna del Negro Francisco the lake is formed by alluvial fans and in the eastern sector by alluvial deposits such as gravels, sands and silts. A number of mountains surround the lake, such as the high Copiapó and the Jotabeche. The Astaburuaga River enters the lake on its eastern shore; it originates on the mountains east of Laguna del Negro Francisco where it is nourished by snowmelt. Other tributaries are the Quebrada Azufre in the northwest, Rio de la Sal in the northeast and Rio La Gallina in the southwest; the tributaries of Laguna del Negro Francisco feature wetlands and marsh vegetation has developed