The Municipality of San Isidro is strategically located at the 
eastern part of Siargao Island. It is bounded in the Northern: Municipality of Burgos; South: in the between Municipalities of Pilar & Del Carmen; East: Binoni Point of the Municipality of Pilar: and West: in between the Municipalities of Del Carmen and San Benito.
San Isidro used as one of the Spanish settlements renamed from the former name Sitio Barodong (Barodong is the local term of mushroom) considering the abundance of mushroom in the area. When a missionary priest came over and settled down in honor of Patron Isadore, the patron and guardian of farmers.
On October 9, 1959 by virtue of Executive Order No. 359, issued by President Carlos P. Garcia, San Isidro became and independent municipality. The Charter Act was made possible through the initiative of the native people who had contributed their morals, donations of lot and financial support to process the necessary documents to make San Isidro a separate town from Numancia. Originally, it has an approximated total land area of 5,500 hectares more or less and it started with one hundred (100) population.
During the period of Mayor Nicarito L. Tiu, Mr. Justines Saragoza and family donated certain parcel of land with an area of 10,430 square meters, more or less covered by Tax Declaration No. 12590 for education of the youth and other improvement thereon. It was received by Mayor Nicarito l. Tiu with Resolution No. 56, s. 1960, dated September 15, 1960 on October 1, 1960 at San Isidro, Surigao del Norte, Philippines.
Originally , San Isidro was composed of thirteen (13) barangays, viz 1) Pacifico 2) Tigasao 3) Landahan now Sta. Paz 4) Del Pilar 5) San Miguel 6) Matin-ao 7) Pelaez 8) Borawin now BuhingCalipay 9) Roxas 10) Macapagal 11) Sto. Nino 12) Tambacan 13) Del Carmen (proper town). However, in 1980 Barangay Matin-ao was given to Municipality of Burgos by Nicarito L. Tiu, thus, reduction of its land area of 5,500 to 4,695 hectares more or less and its population occurred.
People of San Isidro came partly from the neighboring town of Siargao Island but mostly came from the provinces of Bohol and Leyte. They migrated to explore entrepreneurship of selling goods such as tobacco, farm tools and engaging barter trade system. San Isidrohanon or lumad is the common calling of the people living in the locality. They are friendly, accommodating and peace-loving people. Migrants from Socorro in Bucas Grande Island are now scattered living in Barangays, like Barangay Sta. Paz, Sto. Nino, Roxas, Del Pilar and now immigrating to other areas of San Isidro as their second home.
San Isidrohanon prefers a simple living showing hospitality and friendship especially during fiesta celebration. Customs and beliefs of this municipality made use of a traditional practice of diwata, both in sea and land to obtain gifts and graces are now gradually vanishing in the new generation. Read more..