Section 1
SECTION 1 The present boundary line between the Mountain Province and the Provinces of Ilocos Sur and La Union is hereby modified and fixed by moving it eastward to a location beginning approximately at the northeast corner of the present subprovince of Lepanto and running in a direction slightly southwest to the point of intersection of the present boundaries between Amburayan, Lepanto, and Benguet, thence following the present boundary between the subprovinces of Amburayan and Benguet to its intersection with the boundary line of the Province of La Union. The portion of the present subprovince of Lepanto lying east of the new boundary, line is hereby added to the subprovince of Bontoc. All territories west of said line, which include various municipal districts which commercially are naturally tributary to the seaport towns of Ilocos Sur and La Union, are hereby transferred to, and made part of, said provinces. The provincial boards of the provinces concerned need not order a survey of said boundary line but only shall cause the erection of monuments at convenient or necessary points on said line for the guidance of local officials and the public in general. To this end, the provincial boards of Ilocos Sur and La Union, or such representatives as may be duly authorized by them, shall confer with the provincial board of the Mountain Province or its duly authorized representatives with a view to locating and monumenting the boundary line herein fixed, and the line thus monumented, if approved by the Secretary of the Interior, shall be the boundary between the Mountain Province and the Provinces of Ilocos Sur and La Union.