Dateline Resources (ASX:DTR) said it received US government backing in US Federal Court proceedings that challenged the recognition of the company's rights for the Colosseum Mine in California, according to a Monday filing with the Australian bourse.

The National Parks Conservation Association, a non-government organization, challenge an April 2025 letter from the US National Park Service that recognized Dateline's existing rights under the mine's approved operating plan.

In its opposition motion, the US Department of Justice argued the April 2025 letter confirmed the existing legal status of the approved plan, saying that that a new plan of operations is not required, per the filing.

Dateline said the DoJ's submissions are consistent with its own position that activities at Colosseum are in line with existing federal approvals and applicable regulatory requirements.