Macmahon Locks in $38M Underground Contract at Tanami Gold Project

Macmahon Holdings has locked in a $38 million underground contract at the Groundrush Gold Deposit in the Tanami, targeting conversion of over 400,000 ounces of Inferred Resources through a 3.5km decline and 33,000-metre infill drill program — here's what the Macmahon Groundrush underground contract means for investors.
By William Hadrian -
  • Macmahon Holdings has executed a $38 million underground development contract at the Groundrush Gold Deposit in the Tanami region of the Northern Territory, formalising a preferred contractor selection announced on 21 April 2026.
  • The scope includes a 3.5km exploration decline to 350 metres depth, portal and vent establishment, and approximately 33,000 metres of infill drilling — all to be completed within 14 months.
  • The infill drilling program targets conversion of over 400,000 ounces of Inferred Resources to Indicated status, a milestone that would materially de-risk the Groundrush deposit for future development decisions.
  • The contract counterparty is CTP JV Pty Ltd, manager of the Central Tanami Project Joint Venture — a 50:50 JV between MGX Resources Limited (ASX: MGX) and Tanami Gold NL (ASX: TAM).
  • CEO Michael Finnegan flagged "compelling long-term exploration growth potential from multiple gold targets on the tenement package," signalling upside beyond the immediate infill program.
Summarise with AI:

Macmahon secures $38 million underground contract at Groundrush gold project

Macmahon Holdings (ASX: MAH) has executed a contract for underground development at the Groundrush Gold Deposit in the Tanami region of the Northern Territory, formalising a preferred contractor selection announced on 21 April 2026. The agreement, signed through wholly owned subsidiary Macmahon Underground Pty Ltd with CTP JV Pty Ltd (manager of the Central Tanami Project Joint Venture), is valued at approximately $38 million. The CTPJV is a 50:50 joint venture between MGX Resources Limited (ASX: MGX) and Tanami Gold NL (ASX: TAM).

What the contract involves

Decline specifications and drilling program

The core scope centres on developing an exploration decline that will give the joint venture underground access to drill and de-risk a substantial gold resource. Key technical specifications include:

  • Decline length: 3.5km
  • Target depth: 350 metres
  • Scope includes portal and vent establishment
  • Infill drilling program: approximately 33,000 metres
  • Resource conversion target: over 400,000 ounces of Inferred Resources to Indicated status
  • Timeline: 14 months to completion

Groundrush Contract Scope & Technical Specifications

Why resource conversion matters for gold investors

At Groundrush, the infill drilling program enabled by the new decline is targeting conversion of over 400,000 ounces of Inferred Resources.

Managing Director and CEO Michael Finnegan also pointed to “compelling longterm exploration growth potential from multiple gold targets on the tenement package” as additional upside beyond the immediate infill program. That language signals the Groundrush tenement may hold more than what has been drilled to date.

Macmahon’s growing underground portfolio and investment case

Michael Finnegan, Managing Director and Chief Executive Officer

“The commencement of development of the underground decline at Groundrush is an important milestone for this strategically important gold project, which has compelling longterm exploration growth potential from multiple gold targets on the tenement package. We are very proud to be partnering with the Central Tanami Project Joint Venture to collaborate on Groundrush, and we look forward to working closely with them to safely and reliably develop this decline.”

The Groundrush contract is consistent with Macmahon’s positioning as a contractor of choice across Australia. The company offers the complete package of surface mining, underground mining, and civil infrastructure services across Australia, New Zealand, and Southeast Asia, with experience spanning resources, public infrastructure, and renewables projects.

For investors, contract wins like this contribute directly to order book visibility. A $38 million, 14-month engagement provides a defined revenue contribution and demonstrates continued demand for Macmahon’s underground capabilities at active gold development projects.

Key contract details at a glance

The following table summarises the material terms of the Groundrush underground contract.

Detail Specification
Contract value Approximately $38 million
Project Groundrush Gold Deposit
Location Tanami, Northern Territory
Decline length 3.5km
Decline depth 350 metres
Drilling program Approximately 33,000 metres of infill drilling
Resource conversion target Over 400,000 ounces Inferred to Indicated
Timeline 14 months
Joint venture parties MGX Resources Limited (ASX: MGX) and Tanami Gold NL (ASX: TAM) — 50:50

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Frequently Asked Questions

What is the Macmahon Groundrush underground contract?

Macmahon Holdings has executed a $38 million contract through its subsidiary Macmahon Underground Pty Ltd to develop an exploration decline at the Groundrush Gold Deposit in the Tanami region of the Northern Territory, including a 3.5km decline to 350 metres depth and approximately 33,000 metres of infill drilling over 14 months.

Who owns the Groundrush Gold Deposit in the Tanami?

The Groundrush Gold Deposit is held by the Central Tanami Project Joint Venture, a 50:50 JV between MGX Resources Limited (ASX: MGX) and Tanami Gold NL (ASX: TAM), managed by CTP JV Pty Ltd.

What does resource conversion from Inferred to Indicated mean for gold investors?

Converting Inferred Resources to Indicated status means the resource estimate is supported by closer-spaced drilling and carries greater geological confidence, which is typically required before a project can advance to feasibility studies or attract project financing.

How does the Groundrush contract affect Macmahon's order book?

The $38 million, 14-month contract adds a defined revenue contribution to Macmahon's order book, providing forward earnings visibility and demonstrating continued demand for the company's underground mining capabilities at active gold development projects.

When was the Macmahon Groundrush contract announced?

Macmahon was announced as preferred contractor on 21 April 2026, with the formal contract execution announced subsequently through an ASX release confirming the $38 million agreement with CTP JV Pty Ltd.

William Hadrian
By William Hadrian
Partnerships Director
William supports Discovery Alert subscribers across Australia and overseas, helping them tailor alerts, troubleshoot technical issues, and optimise platform settings to suit their workflow.
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