US government joins Dateline’s court fight to lift injunction at California gold and rare earths project

The injunction was originally brought by the National Parks Conservation Association. The court must weigh four factors in its decision: the merits of the appeal, the harm caused by the injunction, the impact of resuming work and where the national interest lies. Dateline and the US government maintain that all four factors weigh in favour of lifting the injunction.

At the heart of the dispute is Dateline’s argument that its Plan of Operations, approved by the Bureau of Land Management in 1985, constitutes a “valid existing right” that survives the later creation of the Mojave National Preserve. The company says the National Park Service recognised that right on three occasions, in 1995, 2024 and again in April 2025.

The US Department of Justice has filed its own motion for a stay, and the Department of War has provided a sworn declaration arguing that exploration at Colosseum is in the national security interests of the United States. The legal push follows the recent passing of Dateline’s long-time chairman, Mark Johnson AO, a former deputy chairman of Macquarie Bank who helped shape the company’s US strategy for more than a decade. The board says it remains determined to progress the project through development and deliver on the groundwork established during his tenure.

Colosseum was originally developed by Bond International Gold in the late 1980s. The mine produced 344,000 ounces of gold before low prices forced its closure in 1993. Dateline acquired the asset from Barrick Gold in 2021 for A$3.4 million including environmental bonds.

A bankable feasibility study completed in May projects US$1.08 billion (A$1.55 billion) in pre-tax free cash flow and a pre-tax net present value of US$785 million (A$1.12 billion). The economics are underpinned by a maiden ore reserve of 20.6 million tonnes grading 0.95 grams of gold per tonne, supporting a 10.4-year operation expected to produce 573,000 ounces at an all-in sustaining cost of US$1825 an ounce. Annual production is forecast to average 75,000 ounces in the first six years, peaking at 102,000 ounces in year six.

The project also carries strategic weight because of its rare earths potential. It sits about 10 kilometres from Mountain Pass, the only major operating rare earths facility in the United States, run by MP Metals. With Washington looking to shore up domestic supplies of critical minerals, the case has taken on a geopolitical dimension.

Separately, Dateline has been advancing other California projects, including the Music Valley heavy rare earths project, where recent rock-chip sampling returned 7.13 per cent total rare earth oxides, and the Argos project, reportedly the largest known strontium deposit in the United States.