Boundary Treaty between Bolivia and Chile of 1866
Article 1. The line of demarcation of the boundaries between Bolivia and Chile in the desert of Atacama, shall, hereafter, be parallel 24o south latitude from the littoral of the Pacific to the eastern limits of Chile, so that Chile on the south and Bolivia on the north will have possession and dominion of the territories extending from the mentioned parallel 24o, exercising in them all acts of jurisdiction and sovereignty corresponding to owners of the land.
The exact survey of the line of demarcation between the two countries shall be undertaken by a commission of properly qualified experts, half of whose members shall be appointed by each one of the high contracting parties.
Once the dividing line is determined it shall be marked by visible and permanent landmarks, the expense of which shall be borne equally by the governments of Bolivia and Chile.
Article 2. Notwithstanding the territorial division specified in the foregoing article, the republics of Bolivia and Chile shall share equally the proceeds of the exploitation of the guano deposits discovered in Mejillones, and in all such further deposits of this same fertilizer which may be discovered in the territory comprised between 23° and 25° south latitude, as well as the export duties which shall be collected upon the minerals mined within the same territorial extension herein previously specified.
Article 3. The Republic of Bolivia undertakes to establish a customs house and open up the port at Mejillones, with the number of officers which the development and commerce may require. This customs house shall be the only revenue office which shall be empowered to receive the proceeds of the guano and the export duties on metals to which the preceding article refers.
The Government of Chile may appoint one or more revenue officers, duly authorized to exercise the right of supervision and inspection of the receipts of the referred-to customs of Mejillones, and to receive directly from the same office quarterly, on in such manner as may be mutually decided upon by both States, the portion of the profit due to Chile to which Article 2 refers.
Article 4. Exemption from all export duties is granted on the products of the territories comprised between 24 o and 25 o south latitude, which may be exported through the port of Mejillones. The natural products of Chile introduced through the port of Mejillones shall likewise be exempt from all import duties.
Article 5. The method of exportation or sale of guano, and the export duties assessed upon minerals, to which Article 2 of the treaty refers, shall be mutually agreed upon by the high contracting parties, either by means of special agreements or according as both may consider more convenient or appropriate.
Article 6. The contracting republics bind themselves not to transfer their rights to the possession or dominion of the territory which is divided between them by the present treaty, in favour of any other State, association or private individual. In case either of them may wish to effect such a transfer, the purchaser may only be the other contracting party.
Article 7. With respect to the losses which the question of limits between Bolivia and Chile has caused, as is well-known, to those individuals who together were the first to exploit effectually the guano deposits of Mejillones and whose work was suspended by order of the authorities of Chile the 17th of February, 1863, the high contracting parties agree to pay equally to said individuals an indemnity of eighty thousand pesos, paid from the per cent of the revenue of the customs house at Mejillones.
(Signed) Signed Juan R. Muñoz Cabrera (L.S.)
(Signed) Alvaro Covarrubias (L.S.)