Republicans in Congress are pushing President-elect Donald Trump to abolish national monuments created by his predecessor, but it remains unclear whether the law grants presidents that power.

Seventy-eight years ago, President Franklin D. Roosevelt’s attorney general told him that presidents lack the authority to abolish national monuments. That written legal opinion, and several opinions offered since then, prevent Trump from rescinding the executive order creating Katahdin Woods and Waters National Monument, according to the Congressional Research Service.

The monument’s superintendent, Tim Hudson, said that the prohibition extends back to 1938, when Homer Cummings wrote that Roosevelt could not abolish the Castle Pinckney National Monument. Early in his presidency, George W. Bush considered abolishing a monument created by his predecessor Bill Clinton, but he never attempted it.

“As far as we know, it has never been done,” Hudson said Wednesday.

That national monuments remain untouchable simply because of a lawyer’s opinion, instead of federal law or case law, is not terribly impressive to many monument opponents, said Bob Meyers, executive director of the Maine Snowmobile Association, which opposed the monument.

Since Trump’s election, local anti-monument groups and officials have been discussing the possibility of Trump reversing President Barack Obama’s executive order of Aug. 24 creating a new national monument out of 87,563 acres in the North Woods of Maine.

Nationwide, questions about the 23 monuments created by Obama prompted the Congressional Research Service to release an 11-page paper on Monday that mentions Cummings’ historic opinion and concludes that there is no precedent for a president abolishing a monument.

But people are still exploring that possibility and other options.

“There seems to be quite a bit of discussion. I see emails, and there’s been conversation. That’s basically it. To me it is not a whole lot different than the buzz you were hearing before the monument was designated,” Meyers said. “There’s not been a lot of focus to it.”

“I am hearing talk from many quarters,” said Anne Mitchell, president of one of the most outspoken anti-monument groups, the Maine Woods Coalition.

The coalition will likely discuss the monument when its members meet in the Bangor area on Nov. 29. The group might approach U.S. Rep. Bruce Poliquin, a monument foe, to hear his thoughts on the issue eventually, Mitchell said.

A statement released Wednesday by Poliquin spokesman Brendan Conley suggested that it is too soon to know what Trump will do.

“The new administration does not take office until [Jan. 20]. Until that time there is no indication there will be a change in policy as it relates to this issue,” Conley said in the statement. “It remains to be seen who will serve in the administration in capacities that affect these issues.”

Conley declined to further discuss the monument.

Pressing what will be a Republican-dominated Congress to abolish the monument, or to transfer it to another agency, such as the state, are among the options available, Meyers said. Congress has abolished 11 monuments, usually, according to a National Park Service history, because “the resources for which the monument was established originally became diminished or were found to be of less than national significance.”

“Obviously, people are still concerned and are still looking at a lot of different avenues. Whether those will play out remains to be seen,” Meyers said. “The way we [snowmobile association members] are viewing it is, what’s done is done.”

The monument’s leading proponents, Burt’s Bees entrepreneur Roxanne Quimby and her son, Lucas St. Clair, did not respond to several requests for comment. David Farmer, spokesman for the campaign to turn Quimby’s approximately 87,500 acres east of Baxter Park into a national park and then monument, left that effort after Obama issued the decree.

When asked how Gov. Paul LePage might approach the monument with Trump in the White House, his spokeswoman, Adrienne Bennett, replied only that the governor was busy preparing his biennial budget. LePage opposed the monument.

The Congressional Research Service report quoted Cummings’ opinion and also found several others who subsequently supported it. Cummings reasoned that the Antiquities Act of 1906 goes no further than authorizing the president to create monuments.

“The statute does not in terms authorize the President to abolish national monuments, and no other statute containing such authority has been suggested,” Cummings wrote.

“My predecessors have held that if public lands are reserved by the President for a particular purpose under express authority of an act of Congress, the President is thereafter without authority to abolish such reservation,” he added.

Trump himself spoke of the issue during a campaign stop on Oct. 15 in Bangor.

“This decision, done at the stroke of a pen without the support of the local community, undermines the people that live and work right here in Maine,” Trump said.