The first business venture of the Marsmans in the Philippines was the location and development of mineral claims in the Cordillera region in 1920. Mining operations in the 1930s led to the establishment of various  businesses including ore refining, air transportation, construction and lumber mills. By the 1950's, mining operations in Benguet,  Bicol, Palawan and Samar were exporting gold, silver, mercury, chromite and copper to different countries including England and Japan.

At present, the Group's mineral properties are concentrated in the province of Camarines Norte. In 1987, United Paragon Mining Corporation was contracted to operate the company's mineral claims in that province. The company receives royalties from all gold ores extracted from the claims.

The impact of mining operations on the environment has always been a concern of the Group. It has made sure that the treatment of mineral tailings are carefully monitored by its operator with the assistance of the Bureau of Mines to ensure the safety of nearby communities. To minimize the harsh effects of open pit mining, massive reforestation projects were undertaken in all areas where mining operations have ceased. In 1977, 30 hectares of mango trees as well as Ipil-ipil were planted in the Palawan property. From 1997 to 1999, thousands of gemilina and pine trees were planted in Camarines Norte in line with the government's reforestation program.