In June 2015, Apex Mining expanded its portfolio by acquiring Itogon-Suyoc Resources, Inc. (ISRI) as a subsidiary. ISRI now manages the mining assets previously held by Itogon-Suyoc Mines, Inc. (ISMI), focusing on the Sangilo Mine in Itogon and the Suyoc Mine in Mankayan.

Originally, the Sangilo Mine produced gold and silver under ISMI until 1996. Its closure was triggered by a confluence of plummeting gold market prices, escalating upkeep expenses, and industrial labor disputes.

Historical records from ISMI show the Suyoc Mine was active from 1934 to 1977. According to US Geological Survey archives, this site was a known source of gold, silver, and copper commodities throughout its tenure.

Current operations at the Sangilo Mine represent a significant milestone, accounting for 10% of total revenue for Apex Mining following its official commercial launch on July 31, 2020. Development continues for the Suyoc Gold Project.

Notably, these assets predate the incorporation of Apex Mining in 1970. The Sangilo site traces its lineage back to 1927, while the Suyoc property began its journey in 1934.