WASHINGTON (AP) – A federal appeals court panel had tough questions Wednesday for opponents of the $3.8 billion, four-state Dakota Access oil pipeline who are arguing to keep a temporary stop of construction in place for a small stretch in North Dakota.

A three-judge panel of the U.S. Court of Appeals for the District of Columbia Circuit already had stopped work for 20 miles on either side of the Missouri River at Lake Oahe while The Standing Rock Sioux Tribe appeals a lower-court ruling from September that let work on the entire pipeline go forward.

Both the U.S. government and the pipeline’s backers oppose the tribe’s request for a continuation of the work stoppage; the pipeline is otherwise nearly complete. However, government agencies said last month they won’t allow construction on government land bordering or under Lake Oahe until they re-evaluates their own decision-making surrounding the pipeline, which is expected to take weeks.

The tribe says the pipeline impacts sites of historic, religious and cultural significance and threatens the water supply for its reservation and millions of people downstream. Its fight has spurred scores of people to join a protest encampment in southern North Dakota that’s on government land, which has been called the largest gathering of Native American tribes in a century. Protesters have said they won’t leave until the pipeline is defeated and plan to stay into the winter.

The panel had a range of questions Wednesday for government, pipeline and tribal lawyers.

Judge Cornelia T.L. Pillard wanted clearer answers about the required consultation the government did with the tribe as well as the boundaries of where the tribe wants work stopped.

“If we’re going to issue an injunction we need to say where it stops,” said Pillard, who told the tribe’s lawyer she was “flummoxed” trying to understand his argument.

Judge Janice Rogers Brown suggested the tribe should have filed its underlying lawsuit before July.

Judge Thomas B. Griffith questioned why the pipeline company wouldn’t halt work near the lake before seeing whether they get the government’s permission to continue construction on government land bordering and under the lake.

“It looks like you’re forcing their hand,” Griffith said.

Pipeline lawyer Miguel Estrada said the company had been told obtaining such permission was a formality. Griffith responded: “It’s not a formality now, is it?”

Estrada also said his clients “went the extra mile” to accommodate tribal concerns.

The judges didn’t say when they’d rule.

–––

Follow Jessica Gresko on Twitter at http://twitter.com/jessicagresko. Her work can be found at http://bigstory.ap.org/content/jessica-gresko.