The history of the OTML dates back to 1963 when copper mineralisation was first identified near the current mine site when a government patrol made contact with the Min people of Star Mountain.
In 1968 the Fubilan Copper-Gold deposit was discovered, and the Kennecott Copper Corporation commenced exploratory drilling.
After the withdrawal of Kennecott in 1975, BHP secured a mining lease of the area and as part of an international consortium, commenced mining feasibility studies culminating in a detailed report to the PNG Government in 1979.
Ok Tedi Mining Limited was incorporated as an entity to operate the project in 1981 and was formed from a partnership between BHP (as the majority shareholder), the PNG Government, Amoco Corporation and Inmet Mining Corporation.
Ok Tedi mine was a green-field operation located in a rugged area of the PNG Western Province that required the development of all the infrastructure including roads, housing, airstrips, power supply and a port located at Kiunga on the Fly River to ship supplies in and copper-gold concentrate out to market.
OTML commenced mining operations in 1984, initially as a gold mine to exploit the gold-rich cap on the Mt. Fubilan deposit, and then as a copper-gold mine in 1987 for the bulk of the ore body.
BHP exited OTML in 2002, vesting its interest to the Papua New Guinea Sustainable Development Program (PNGSDP).
In 2012, OTML became a fully owned Papua New Guinea company when Inmet Mining Corporation shares were bought out by OTML.
In 2013, OTML became a state-owned enterprise when the PNGSDP shares were cancelled, and the Government of PNG increased its direct ownership to 87.8 percent.
Originally the mine was planned to close in 2010. However, following an extensive community consultation process and revised mine plans, the mine life was extended to 2025.