Alto Palena–Encuentro River dispute
The Alto Palena-Encuentro River border dispute was a territorial dispute between the Argentine Republic and the Republic of Chile over the demarcation of the boundary between landmarks XVI and XVII of their common border in the valleys located north of General Vintter/Palena Lake (formerly General Paz Lake), and was resolved on November 24, 1966, by the arbitral ruling of Queen Elizabeth II of the United Kingdom.
The ruling divided the disputed territory between the two countries, distributing it between the Palena commune in the Palena Province, Los Lagos Region in Chile (Regions created afterwards), and the Languiñeo Department in the Chubut Province of Argentina.