Interior Secretary Ryan Zinke wants to dial back the Obama administration's eleventh-hour designation of the Bear Ears National Monument in Utah by recommending to President Trump that the action be revised and the boundaries changed.

"The recommendation is to revise the existing boundaries," Zinke told reporters Monday, outlining interim recommendations ahead of a final review that will come later this summer.

The revised boundaries would protect the area's historic and prehistoric objects, which Zinke said is the "responsibility" of the federal government.

"There is no doubt that there are historic and prehistoric structures and other objects of scientific interest ... within the Bears Ears Monument," he said. These "items and objects can be segregated and reasonably separated," he said. The recommendations went to the president over the weekend.

Zinke also is asking Congress to grant indigenous tribes the ability to co-manage the lands with the federal government.

"We are asking Congress to authorize co-management of the revised boundaries and monuments co-managed by the tribes," Zinke said. He talked with tribes in the region in May, saying it is obvious to him that they have created a management process.

The 45-day interim recommendations are part of Trump's executive order directing Zinke to conduct a review of a number of the Obama administration's actions to significantly expand existing monument areas. Former President Barack Obama's monument designations would make oil and natural gas drilling and other mining activities off limits in many cases.

Environmentalists strongly opposed Monday's interim decision, saying revising the boundaries is a "slap in the face" to the tribes who share cultural and religious ties to the land, according to the group Earthjustice.

It also would "violate both the Antiquities Act and the separation of powers doctrine," said Heidi McIntosh, Earthjustice's managing attorney. "The president simply lacks the authority to change a national monument designation under the Antiquities Act, our country's century-old law that protects some of our most scenic and historic landscapes."