TL;DR — Key Purpose
The boundary line between the municipalities of Allen and San Isidro, Province of Samar, shall be the center of the Mawo River up to the intersection of Mawo River and Igot River (San Ramon Creek), and from the center of the mount of Igot River to the intersection of Igot River and Binalabag Creek which runs eastward up to the boundary of the Municipality of San Jose.
REPUBLIC ACT No. 2511 An Act Fixing the Boundary Line Between the Municipalities of Allen and San Isidro Province of Samar Be it enacted by the Senate and House of Representatives of the Philippine Congress Assembled: Section 1. The boundary line between the municipalities of Allen and San Isidro, Province of Samar, shall be the center of the Mawo River up to the intersection of Mawo River and Igot River (San Ramon Creek), and from the center of the mount of Igot River to the intersection of Igot River and Binalabag Creek which runs eastward up to the boundary of the Municipality of San Jose. 1шphi1 Section 2. The Municipality of San Isidro shall include the barrios of San Ramon, Erenas, San Juan, Palanit, Veriato, Acedillo, Tangolan, Buenavista, Among, Happy Valley, Caaguit-itan, Corocolab-og and Caglanipao. Section 3. This Act shall take effect upon its approval. Approved: June 21, 1959. The Lawphil Project - Arellano Law Foundation