Chile and Bolivia sign the Treaty of Peace and Friendship, delimiting the border between the two countries.

The Treaty of Peace and Friendship of 1904 between Chile and Bolivia was signed in Santiago de Chile on October 20, 1904, to delineate the boundary through 96 specified points between Cerro Zapaleri and Cerro Chipe and to regulate the relations between the two countries 20 years after the end of the War of the Pacific.

The Bolivia–Chile boundary is about 861 kilometres (535 mi) long and is demarcated by pillars in the Andes. Most of the boundary consists of straight lines between high mountain peaks. From the Argentina–Bolivia–Chile tripoint of Cerro Zapaleri, it extends northward through more than five degrees of latitude to the Peru–Bolivia–Chile tripoint at 17° 29' 55.0" S. latitude and 69° 28' 28.8" W. longitude.