Native American tribes and environmentalists want a U.S. appeals court to weigh in on their request to halt construction along part of a $10 billion transmission line that will carry wind-generated electricity from New Mexico to customers as far away as California.

The disputed stretch of the SunZia Transmission line is in southern Arizona’s San Pedro Valley. The tribes and others argue that the U.S. Interior Department and Bureau of Land Management failed to recognize the cultural significance of the area before approving the route of the massive project in 2015.

SunZia is among the projects that supporters say will bolster President Joe Biden’s agenda for cutting greenhouse gas emissions. The planned 550-mile (885-kilometer) conduit would carry more than 3,500 megawatts of wind power to 3 million people.

A U.S. district judge rejected earlier efforts to stall the work while the merits of the case play out in court, but the tribes and other plaintiffs opted Wednesday to ask the 9th U.S. Circuit Court of Appeals to intervene.