Hidden Valley Mine Overview looking North North-East
Hidden Valley Mine Overview looking North North-East
Quick Facts

Location: Morobe Province - 90 kilometres south-west of Lae
Expected annual production: + 250,000 ounces of gold - 4 million ounces of silver
Expected mine life: 14 years based on current reserves
Mining method: open pit

Workforce: Around 2,000 employees and contractors (95% Papua New Guinean’s with 50% from local communities)
Ownership: Morobe Mining Joint Venture (50% Newcrest Mining: 50% Harmony Gold)

About us

The mine operates in accordance with a Memorandum of Agreement (MoA) between HVJV, local landowners and all levels of government. This agreement sets out a preference for employment of landowner and local residents ahead of those from other provinces and offshore employees when qualifications and experience are equivalent.

As per the MoA, employees are categorised into five tiers:

Tier 1 – Landowners from the Villages of Kwembu, Winima and Nauti
Tier 2 – Wau/ Bulolo residents in the Bulolo District
Tier 3 – Morobe residents
Tier 4 – PNG Citizens
Tier 5 – Non-Citizens

Most employees live in the accommodation village on site while in the work period of their rosters. 15% of the total permanent workforce at Hidden Valley, are women. Ninety percent are from PNG, and over half come from local communities.

Top of page


Construction of the Hidden Valley open pit gold and silver mine began in 2007 with the bulk of the work completed towards mid 2009. First gold pour commenced only recently in June 2009 and the project is currently fully operational.

Annual production at Hidden Valley mine is expected to be around +250,000 ounces of gold and 4 million ounces of silver. Operating at full design capacity, Hidden Valley which currently has a 14-year mine life, will process an estimated 4.7 million tonnes of ore annually from two open pits located approximately 5 kilometres apart: the smaller Hamata pit which exploits the Hamata gold ore body, and the larger pit which exploits the Hidden Valley and Kaveroi (HVK) gold and silver ore bodies.

Ore is delivered by truck to the Hamata and Hidden Valley crusher stations. Crushed Hamata ore is delivered by conventional conveyor to the primary stockpile and Hidden Valley ore is delivered via the 4.5 kilometre overland pipe conveyor extending from the HVK pit to the Hamata processing plant to the same stockpile.

Overland conveyor
Two jaw crushers are used in series to prepare the ore for transport and for feed to the SAG mill and the 4.5km long pipe conveyor is a vital link between the mine and processing plant enabling the transportation of ore from the HVK pit to be fed straight to the SAG mill.

The processing plant utilises conventional gravity and CIL circuits for gold and a Merill Crowe circuit for silver. The mill has been constructed to process a nominal 4.2 Mtpa of ore from the two pits, with de-bottlenecking of the plant planned up to 4.7 Mtpa. When fully commissioned, the process plant will treat 4.7 million Tonnes of ore per year.

Hamata open pit operations at the Hidden Valley mine
Hamata open pit operations at the Hidden Valley mine
Hidden Valley is also the first major open pit mine in PNG to build a Tailings Storage Facility (TSF) to contain all tailings permitted under the new Environment Act 2000.

Mill Maintenance Foremen
Tailing Storge Facility

Top of page


Safety is of the greatest importance both on and off site. It is the culture of every mine in the world and one that Hidden Valley mine intends to excel at.

Our goal is to make Hidden Valley mine, the safest in the country.

Everyone that visits the mine site is issued with personal protection equipment (PPE) when entering the mine site.

Top of page

Community & Regional Development

Hidden Valley Mine identifies Health, Education, Agriculture and Infrastructure Development as the four pillars of its five year community and regional development plan, for the people of Wau / Bulolo district and Morobe Province.

These include roads, bridges, classrooms and clinics, water supplies, health and sanitation awareness, training in fish farming, cocoa and coffee growing, and other extension services.

Mill Maintenance Foremen
Coffee training for local stakeholders at Biawen Village in the Wau Bulolo District.
To implement these programs Hidden Valley entered into Public Private Partnerships (PPP) with host communities including government departments, Business Organisations and Non - Government Organisations (NGO’s) Lutheran Development Services (LDS); Adventist Development Relief Agency (ADRA); Bris Kanda Incorporated; Mainland Holdings Limited; National and Provincial Departments of Health, Education and Works; National Agricultural Research Institute; Small Business Development Corporation, Morobe Fisheries Management Authority (MFMA). Further relationships with PNG Statutory bodies Coffee Industry Cooperation (CIC) Goroka and Cocoa and Coconut Research Institute (CCRI) in Madang are also being developed to strengthen support for Cocoa and Coffee programs for stakeholder communities.

Top of page


Our vision is to create a world class mineral province within PNG


Honesty, Integrity, Respect, Working Together, Courage, Creativity & Innovation and Commitment to our people


Discovering, developing and operating gold mines in Morobe Province to build a sustainable long term business to benefit all our stakeholders