Message to the Senate Transmitting Treaty on the United States-Mexico Boundary.

To the Senate of the United States:

With a view to receiving the advice and consent of the Senate to ratification, I transmit herewith the treaty to resolve pending boundary differences and maintain the Rio Grande and Colorado River as the international boundary between the United States of America and the United Mexican States, signed at Mexico City on November 23, 1970.

I transmit also, for the information of the Senate, the report of the Secretary of State with respect to the treaty.

This treaty, it is believed, constitutes as fair a settlement as can be negotiated of all pending boundary differences and uncertainties with Mexico, and represents a comprehensive attempt on the part of the two Governments to deal with existing and future boundary problems.

The provisions of the treaty are outlined and explained in the enclosed report of the Secretary of State. Under the treaty the Governments would settle the existing disputes and uncertainties regarding the location of the boundary along the Rio Grande and off both coasts, and would establish new procedures for handling the river movements that have occasioned differences and uncertainties in the past. Under it there would be assigned to the United States approximately 2,079 acres of land about which there has been question as to national sovereignty, and to Mexico about 3,326 acres about which there has been similar doubt.

The treaty would establish a permanent maritime boundary in the Gulf of Mexico where, due to migration of the mouth of the Rio Grande, it has been indefinite and moving for more than a century, as well as in the Pacific Ocean. Henceforth, mariners and potential lessors and lessees of the seabed would be able to ascertain precisely the extent of the jurisdiction of each nation.

The treaty would also provide measures to avert in the future significant loss of territory to either country because of the inevitable movements of the boundary rivers. The importance of these provisions is indicated by the fact that in a century more than 240 tracts have been cut from one country to the other, effecting a transfer of about 20,800 acres from Mexico to the United States and about 15,300 acres from the United States to Mexico, with the attendant uncertainty about the location of the boundary, and the inconvenience and personal loss, to some of the owners of the land.

The settlement unfortunately will entail loss to the Presidio Valley of Texas of a considerable part of its irrigable land. While this land belonged to Mexico in 1852, it has long been occupied and much of it farmed by American citizens. With only a limited amount of irrigable land available, the economic base of the valley will be adversely affected. Following the precedent of the Chamizal settlement of 1963, when lands also had to be transferred to Mexico, I intend to recommend inclusion in enabling legislation of specific measures to relieve the people of the valley of financial loss and assist them in adjusting to the requirements of the settlement. This assistance should alleviate the burden of the settlement which the valley and its residents are ill-prepared to bear, and for which they have had no responsibility.

In the absence of the detailed investigations that can be undertaken only after ratification of the treaty, the U.S. Section of the International Boundary and Water Commission has been able to prepare only preliminary estimates of the cost of the works required for implementation of the treaty. In his report the Secretary of State presents preliminary estimates totaling $10,368,000 for the United States share of the work that should be performed over the next two years. In addition to normal maintenance, the treaty would commit the United States to a continuing program to restrain the boundary rivers in their courses and avert loss of territory through the shifting of sizeable tracts from one country to the other. This program is expected to require an average expenditure of not more than $400,000 per year. The Government of Mexico would, of course, perform its share of this work, and the total continuing obligation for both countries would diminish as the Commission succeeds in stabilizing the course of the rivers where shifting seems most likely.

I believe that the proposed comprehensive boundary settlement admirably reflects the mutual respect and understanding in which the Governments of the United States and Mexico conduct their relations and the constructive spirit with which they approach common border problems. I strongly recommend that the Senate of the United States advise and consent to the ratification of the treaty as promptly as appropriate procedures permit.

RICHARD NIXON

The White House

April 21, 1971