Caribou graze on the coastal plain of the Arctic National Wildlife Refuge, with the Brooks Range as a backdrop. (USFWS)

The Gwich’in Steering Committee and more than a dozen environmental groups are suing the Trump administration over its controversial plan to open up a northern part of the Arctic National Wildlife Refuge to oil and gas development.

The two lawsuits filed Monday challenge the administration’s plan for drilling in the Arctic Refuge’s coastal plain. They argue that the Bureau of Land Management’s environmental review process failed to follow numerous laws meant to protect wildlife, land, water and people. 

“The remedy that we’re seeking is to throw out this illegal decision as well as any lease sale or leases that rely on it,” said Victoria Clark, executive director of Trustees for Alaska, the Anchorage-based firm representing the Gwich’in Steering Committee and other groups.

[Read the lawsuit filed by Trustees of Alaska on behalf of 13 clients here.]

The lawsuits come a week after BLM finalized its plans for development in the 1.6-million-acre coastal plain — an area roughly the size of Delaware that makes up about 8% of the vast Arctic Refuge. It’s a place where caribou migrate, polar bears den and migratory birds feed. It’s also an area believed to hold billions of barrels of untapped oil. 

RELATED: Trump Administration finalizes plan for oil drilling in Arctic Refuge

Interior Secretary David Bernhardt has said the federal government could auction off drilling rights in the coastal plain by the end of the year.

That’s why the groups had to quickly move forward with their lawsuits, Clark said. Once leases are issued, it could be more difficult to reverse course.

“We have an administration that is just steamrolling along trying to get these decisions made,” she said.

BLM’s development plan stems from legislation approved by Congress in 2017 that called for two lease sales in a coastal section of the Arctic Refuge within seven years.

In response to the lawsuits, BLM released a statement Monday saying that its plan for where and when development can take place “includes extensive protections for wildlife, including caribou and polar bears.”

“This is a congressionally mandated energy development program that leaves 92% of the refuge completely off-limits to development,” it said. 

But the lawsuits argue that BLM is downplaying the impacts of drilling, and say that oil and gas development will cause irreparable harm to wildlife, the tundra and the climate. 

“Developing Alaska’s last wild places would be a death sentence for polar bears and other threatened Arctic species. The oil industry just doesn’t belong in the Arctic National Wildlife Refuge,” said a statement from Kristen Monsell, a senior attorney at the Center for Biological Diversity, a group behind the second lawsuit.

[Read the lawsuit filed by the Center for Biological Diversity and other environmental groups here.]

On a call with reporters Monday, Gwich’in Steering Committee’s executive director Bernadette Demientieff said the Gwich’in people feel attacked by the government.

“We are not asking for anything, but the ability to continue to live and thrive off the land that has sustained us for thousands and thousands of years,” she said.

RELATED: In Arctic Village, Gwich’in leaders say the fight to stop drilling in the Arctic Refuge isn’t over

Demientieff is from the Yukon River community of Fort Yukon, and she’s one of the highest profile leaders among the Gwich’in, an indigenous group spread between Alaska and Canada whose members harvest caribou that give birth in the Arctic Refuge.

Demientieff vowed: “We will give you one heck of a fight.” 

Reach reporter Tegan Hanlon at thanlon@alaskapublic.org or 907-550-8447.