The Tonto National Forest has released a final Environmental Impact Statement for the proposed Resolution Copper Mine, paving the way for one of the largest copper mines in the U.S. in a section of the forest known as Oak Flat.

The mine would be located about 60 miles east of Phoenix near Superior. The grassroots group Apache Stronghold filed suit in U.S. District Court on Tuesday to delay the release and filed a temporary restraining order Wednesday.

The Apache group says that COVID-19 made it difficult to weigh in during the environmental-impact process, but it has been fast-tracked in the final days of the Trump administration.

“There’s already been litigation filed, there will be more, and it will be shown that this whole project is illegal,” said Randy Serraglio, of the Center for Biological Diversity.

Serraglio says the Biden administration could withdraw the impact statement, and that Congress could step in to protect Oak Flat.