Several new environmental rules are scheduled to go into place before Trump takes office, including a new Bureau of Land Management rule governing venting and flaring by oil drilling rigs.

The Interior Department's Office of Surface Mining Reclamation and Enforcement plans to finalize its Stream Protection Rule, which regulates coal mining near water sources, and rules from the Office of Natural Resource Revenue and the Fish and Wildlife Service are also slated to take effect.

"We've seen a whole trajectory here of the Obama administration leaning into conservation and climate issues," said Alex Taurel, deputy legislative director at the League of Conservation Voters.

During his eight years in office, Obama has designated more than 265 million acres of land and water, more than any other president since the American Antiquities Act gave the chief executive the power to designate public lands for protection in 1906.

"If you look at the president's record, nobody has done more to address climate change than this president, and he's protected more land and water than any president in history," Taurel said.

Activists hope Obama will use his final weeks in office to add to his totals.

Taurel cited Bears Ears, a 1.9 million-acre area in southern Utah, and Gold Butte, 360,000 acres of territory in Arizona where early settlers mined, as two areas where the administration may consider extending protections.

Critics who say the new rules kill jobs and limit economic potential see the Obama administration rushing to clear as much paper as possible following Trump's surprise win.

The haste with which the administration is promulgating the rules, critics say, may mean the final result isn't as effective as possible, or necessary.

"We're looking at the stack of regulations and the fact that the agencies are just as ill-prepared to make these new regulations work as we are confused on how we can possibly comply in such a short time," said Kathleen Sgamma, vice president of government and public affairs at the Western Energy Alliance in Denver.

Jessica Kershaw, a spokeswoman for the Interior Department, said in an email the administration is "finishing the business we started and in some cases, finishing the business of prior administrations where decisions weren't complete when we took the helm."

Trump has promised to roll back many Obama-era rules and executive orders on his first day in the White House. But conservationists hope the Obama administration is structuring some of the late environmental regulations in ways that will make it more difficult for a subsequent administration to reverse.

Whether implementing new requirements or rolling back existing ones, any rule changes require months of public notice, comments and meetings. Speeding that process opens a future Interior Department up to litigation that would almost certainly lead to further delays. For example, one Fish and Wildlife decision not to include the greater sage grouse on the Endangered Species List took a decade and a half to resolve in court.

"There may be some pathways where they could speed up [the process of rolling back regulations]. But if they do take those pathways I think they're at more risk of litigation," Taurel said.

Resetting what the Obama administration has already accomplished, he added, "is going to be harder than they think."

Those who don't want to see the rules finalized before Trump takes over want to see Congress play a more active role.

Sgamma said Congress should consider using the Congressional Review Act, a 1996 law passed as part of the Contract with America that gives the House and Senate 60 legislative days to disapprove of federal regulations.

That period would extend well into the new Congress.

"The paralysis that would result, particularly on federal lands, if all these ill-defined rules go into effect at the same time means that many should be overturned," Sgamma said.