• Preparation for Groundrush gold deposit exploration decline with Macmahon selected as preferred contractor.
• Resource definition drilling at Jims gold deposit to enhance open pit potential.
• Koolan Island low-grade stockpile shipping program continues to offset rehabilitation costs.
• Binding conditional agreement to sell Koolan Island operation to Crestlink for $20.2 million.
• MGX share of CTPJV expenditure totalled $4.7 million for the quarter.

Mount Gibson Iron Ltd. (MGX) reported its June 2026 Quarter Activities, highlighting key developments in its Central Tanami Project Joint Venture (CTPJV) and the Koolan Island operation. At CTPJV, preparations for the Groundrush gold deposit exploration decline with Macmahon as the preferred contractor are underway, with site works scheduled to commence in August. Resource definition drilling at the Jims gold deposit aims to enhance open pit potential. MGX's share of CTPJV expenditure totalled $4.7 million for the quarter. Meanwhile, the Koolan Island low-grade stockpile shipping program continued, generating $5.8 million in net cashflow after rehabilitation costs. Koolan Island shipped 0.94 million wet metric tonnes (Mwmt) of low-grade iron ore in the quarter, lifting total sales for FY26 to 2.68 Mwmt. A binding conditional agreement was executed to sell the Koolan Island operation to infrastructure and logistics group Crestlink for up-front and deferred payments totalling at least $20.2 million and a future revenue share component of up to a further $5 million (CPI indexed). Crestlink will assume the rehabilitation obligations remaining at transaction completion, anticipated to be in the region of $30 million. Completion is targeted for late 2026 but can be extended to 31 March 2027.

MGX's 50% share of CTPJV expenditure totalled $4.7 million for the quarter.

Activities for the CTPJV in the coming six months will focus on commencement of Groundrush site works and construction of the underground exploration decline, continuation of the resource definition drilling activities, repairs and improvements to the site accommodation camp and utilities infrastructure, and advancement of key permitting workstreams.