Tanami Gold NL has executed a formal $38 million agreement with Macmahon Underground Pty Ltd to construct the Groundrush underground decline at the Central Tanami Project in the Northern Territory.

The transaction moves the 50/50 joint venture forward from its April preferred contractor selection into formal contract execution. On-surface works, including laydown preparation and in-pit ramp re-establishment, are already underway, with portal construction scheduled to start in September.

The 14-month construction program will deliver an initial 3.5-kilometer decline extending to a depth of approximately 350 meters. Once established, the underground development will provide drilling platforms to support 33,000 meters of resource definition drilling targeting the Groundrush Gold Deposit down to a depth of roughly 650 meters. The primary objective is to convert more than 400,000 ounces of gold currently classified as Inferred Resources into the higher-confidence Indicated category to support future mine design.

The Central Tanami Project Joint Venture, held equally by Tanami Gold and MGX Resources Limited following MGX’s acquisition of its 50% interest from Northern Star Resources for $50 million, aims to advance the project toward a development decision in 2027. Tanami Gold funded its joint venture obligations following a fully underwritten renounceable rights issue in June 2026 that raised $50.3 million.

“The commencement of the Groundrush decline represents a key milestone in the CTPJV's efforts in advancing the project .Working with our JV Partner, MGX, both companies continue to progress the project and the establishment of a major new gold operation in the Northern Territory.”

— Brett Smith, Executive Director

The broader joint venture asset base hosts a total Mineral Resource of 31 million tonnes at 2.8 grams per tonne gold for 2.8 million ounces, which includes 11 million tonnes grading 3.3 grams per tonne for 1.2 million ounces contained within the Groundrush deposit. Alongside decline preparations, site activities include ongoing resource definition drilling at the Jims Gold Deposit—which previously operated 25 years ago and holds 2.6 million tonnes at 2.7 grams per tonne for 220,000 ounces—alongside refurbishments to the local accommodation camp and utilities infrastructure.

Read the full announcement: Groundrush Decline Agreement Signed