El Salvador–Guatemala border

A commission with a neutral member

In August 1935 El Salvador and Guatemala agreed by exchange of notes to fix their border for good. A Mixed Boundary Commission, with one delegate from each country and a third from a neutral state, mapped it from aerial photographs. In 1936 the two and Honduras accepted Cerro Montecristo, 3,926 feet high, as their three-way meeting point.^[1]

The treaty of 9 April 1938 set the line on the commission’s recommendations. It also said that if a border river later moved, the border would not move with it. The commission finished building 530 monuments and pillars in September 1940.^[1]

Ravines, ranches and a lake

In the north the line winds through ravines and rivers and along the edges of named estates and ranches, such as the “Ostua” ranch in El Salvador and the “Juan Martin” ranch in Guatemala. It crosses Lake Güija between two peninsulas, passes over the Chingo volcano, and then follows the Chingo, Pampe and Paz rivers to the Pacific.^[1]

“…thence crossing the lake of Guija in a straight line to the most northerly point of the peninsula known as “Tipa Afuera”…”^[1]