Trump's order reduces the size of the iconic Grand Staircase-Escalante National Monument in Utah, where numerous dinosaur fossils have been found.
President Trump called for two wilderness areas shielded from development in Utah to be reduced by about two million acres, reversing protections introduced by Barack Obama and Bill Clinton and teeing up a legal battle.
Trump will also ask Congress to look at the areas that are being removed from the current monuments to consider designating some as a national conservation or national recreation areas, and create a co-management structure for tribes, an administration official said.
The Bears Ears National Monument will shrink 85% to 201,876 acres, and the Grand Staircase-Escalante National Monument will be cut by 39% to 1 million acres.
The reasoning behind the move is to designate as protected "the smallest area compatible with the protection of the objects of scientific or historic interest", and the proclamation also opens the newly public lands to "disposition under all laws relating to mineral and geothermal leasing; and location, entry, and patent under the mining laws".
When President Obama designated Bears Ears a national monument a year ago, it was a huge victory for five Utah tribes - the Navajo Nation, Ute Mountain Ute Tribe, Ute Indian Tribe, Hopi, and the Pueblo of Zuni - who came together in 2015 to push for the preservation of what they estimate are 100,000 cultural and ancestral sites, some dating back to 1300 AD, in the region.
The Outdoor Industry Association said the move would hurt the economy and jobs, two of Trump's declared priorities.
"These are federal lands, these are our lands, they're everyone's, they're not just one state's" lands", said Mary Hertert, protester.
"Through the Antiquities Act, Congress delegated to the president the limited authority to designate national monuments and retained to itself the power to revoke or modify national monuments". The details of that report will be released Tuesday, he said.
Zinke also has recommended allowing logging at a newly designated monument in ME and urges more grazing, hunting and fishing at two sites in New Mexico.
"Federal protected lands are to preserve and protect the natural and cultural history forever and for future generations", Lisa Eckert, protester, said. The Navajo Nation, the Hopi, the Ute Mountain Ute, the Ute Indian Tribe of the Uintah and Ouray Reservation and the Zuni tribes all are in support of Bears Ears National Monument.
Both parks, or monuments as they are called, are in the dramatic Southern Utah red rock country.
But Zinke said he will also recommend changes to a handful of other monuments. The federal government controls about two thirds of Utah.