Southern Patagonian Ice Field dispute

The difficulties that may arise due to the existence of certain valleys formed by the bifurcation of the Cordillera and where the dividing line of the waters is not clear, shall be resolved amicably by two experts appointed, one from each party.

[13]On 20 August 1888, an agreement was signed to carry out the demarcation of the limits according to the 1881 treaty, appointing the experts Diego Barros Arana for Chile and Octavio Pico Burgess for Argentina.

[18] In January 1894, the Chilean expert declared that he understood that the main chain of the Andes was the uninterrupted line of peaks that divide the waters and that form the separation of the basins or tributary hydrographic regions of the Atlantic to the east and the Pacific to the west.

The Argentine expert Norberto Quirno Costa (Pico's replacement) replied that they had no authority to define the meaning of the main chain of the Andes as they were only demarcators.

In the minutes of 1 October 1898, signed by Diego Barros Arana and Francisco Moreno (Quirno Costa's replacement, who resigned in September 1896) and by his assistants Clemente Onelli (from Argentina) y Alejandro Bertrand (from Chile), the experts: agree with the points and stretches indicated [...] 331 and 332 [...], resolv[ing] to accept them as forming part of the dividing line [...] between the Republic of Argentina and the Republic of Chile [...].On the attached map, point 331 is Fitz Roy and 332 is Mount Stokes, both being agreed as boundary markers, although the former is not on the watershed and was taken as a natural landmark.

[16] When the experts could not agree on different stretches of the border, it was decided in 1898 to resort to Article VI paragraph 2 of the 1881 Boundary Treaty and request Queen Victoria of the United Kingdom for an arbitration ruling on the issue, who appointed three British judges.

[24] In 1941, the protocol regarding the repositioning of milestones on the Argentine–Chilean border was signed, creating the Joint Commission on Boundaries (COMIX), formed by technicians from both countries.

[18] In Chile, it was argued that the experts identified in 1898 as intermediate summits between the Fitz Roy and Stokes mounts: Torre, Huemul, Campana, Murallón, Agassiz (Old Bertrand), Bolados, Peineta, and Mayo.

On 2 August 1991, Presidents Menem and Aylwin signed an agreement to draw a polygonal line to equitably divide the disputed territory from Fitz Roy to Stokes,[26] leaving aside what had been agreed upon in 1881 and 1893.

[27][18] In his presentation to the congress on 27 February 1992, the Argentine minister Guido Di Tella argued that the polygonal shape had been agreed upon because of the geophysical impossibility to determine where the high peaks that divide waters are located.

[18] In 1994, the Laguna del Desierto incident was solved which involved territory of the Ice Field, an international tribunal awarded almost the whole zone to Argentina.

[25][31] The agreement maintains what was signed in the 1881 treaty, high peaks that divide waters and respects the continental watershed, except in some sectors where straight lines are drawn.

[33] This sector corresponds to a rectangular territory that goes from a few kilometers north of the summit of Fitz Roy to Mount Murallón, in which there is an area without boundary demarcation.

Within this area, however, the agreement itself demarcated the boundary from Fitz Roy to a few kilometers to the southwest (point B), and, from the same mountain to the north, it was defined by means of the 1994 Laguna del Desierto arbitration award.

In February 2006, Ricardo Lagos[37] appeared in a photo with the head of the Air Force, General Osvaldo Sarabia, in the undefined border area, this caused controversy with Argentina.

After Chilean diplomatic protests, the Argentine government withdrew the map temporally and urged Chile to expedite the "demarcation" of the international border according to the 1998 agreement.

Not having received to date no response from Chile to the aforementioned invitation, this Ministry of Foreign Affairs has instructed the Argentine International Boundary Commission to reiterate to its counterpart the need to begin the demarcation work as soon as possible and to propose the implementation of the first tasks necessary for this purpose.The exchange of communiques had occurred due to the Chilean government's complaint regarding the non-use of the rectangle of the undefined border area on maps of the Argentine Secretariat of Tourism.

[66][67] The same year there was a controversy since the National Forest Corporation (from Chile) installed a dome in the Circo de los Altares which its southern part is claimed by both countries.