As President Barack Obama considers expanding on his already record-breaking use of the Antiquities Act to protect federal lands as national monuments, pushback is coming from states such as Utah, where the latest battle is unfolding.

Since his election, Obama has designated or enlarged 22 national monuments, setting aside 4 million acres of land and adding 261.3 million acres of water and reefs in the Pacific Ocean near Hawaii for preservation under the Antiquities Act. The vast acreage being preserved in the Pacific puts Obama at the top of the list of presidents in terms of conservation, and he is pushing to do more.

But those efforts could be stalled by a fight over a request from Native American tribes and environmental groups to designate 1.9 million acres of federal land in southern Utah as the Bears Ears National Monument. The lands on sweeping plateaus east of the Colorado River are filled with ancient artifacts, burial grounds and sites considered sacred by the Navajos and other tribes, and they include scenic areas managed by three federal agencies, including the National Park Service.

Under the Antiquities Act, the president has the power to authorize the preservation of federal land that holds historic, scientific and/or archeological interest. Once designated, the land would be off limits to new development such as gas and oil exploration and grazing allotments, although existing leases would continue.

“Obama has an incredible opportunity before him with the Utah proposal,” said Sharon Buccino, director for the Natural Resources Defense Council’s Land and Wildlife program. The decision has the ability to “make or break” Obama’s conservationist legacy, Buccino says, mainly because it would protect so many acres.

Republicans in the Utah congressional delegation, led by Reps. Rob Bishop and Jason Chaffetz, firmly oppose the Bears Ears proposal, still under Interior Department review.

“We believe the wisest land-use decisions are made with community involvement and local support,” the lawmakers wrote in a Feb. 12 letter to Obama. “Use of the Antiquities Act within [Utah] will be met with fierce local opposition and will further polarize federal land-use discussions for years, if not decades.”

Bishop and Chaffetz are proposing legislation they say would be an alternative to a monument designation, with some of the federal lands set aside for conservation, some for recreation and others for economic development, according to their discussion draft.

Much of the distrust of the national monument designation process in Utah stems from 20 years ago when the Clinton administration set aside 2 million acres as the Grand Staircase-Escalante National Monument despite state and local opposition. Since then, opposition has been building to the federal government’s land policy decisions, which affect about two-thirds of Utah’s land area.

In 2012, Republican Gov. Gary Herbert signed legislation that would require the United States to transfer all federal lands to the state for management, excluding five national parks and 33 designated wilderness areas.

The law set a 2014 deadline for the transfer, and the state has already begun to look into legal action to enforce it.

“Gov. Herbert believes that the state of Utah has three paths forward on this issue: negotiation, legislation, and litigation,” the governor’s spokesman, Jon Cox, said in an email.

“He would prefer a legislative resolution to the many public lands issues Utah faces, but unfortunately that isn’t always possible,” Cox said. “The state of Utah is actively pursuing several of these cases in court right now and reserves the right to pursue additional legal recourse in the future.”

Since the beginning of last year, 14 states, mainly in the West, have either passed or introduced legislation to support the transfer of federal land to the states for management, according to a January analysis by the National Conference of State Legislatures.

“The biggest benefit the states are exploring is the economic benefit from land transfer, and whether administration costs make it worthwhile,” said NCSL policy specialist Mindy Bridges. “Another trend within the legislation is it would be more geared toward Bureau of Land Management land, specifically not including congressionally delegated land,” such as national parks and wilderness preserves.

The Public Lands Council, which represents ranchers and businesses that depend on federal land, has no problem with federal protection of tribal lands, said the group’s executive director, Ethan Lane. But when it ties together millions of acres to protect the same site, it effectively shuts down economic development on lands peripheral to the monuments, he said.

“If you protect millions of acres of land, what does that do to the communities and local business that depend on the federal land? It kills them,” Lane said.

As for the Bears Ears proposal, the Interior Department said there would be an extensive public comment period before any decision is made.