SALT LAKE CITY — Three rural counties in Utah impacted by monument designations 20 years apart want to intervene in lawsuits against the Trump administration that reduced the original boundaries.

Kane, Garfield and San Juan counties say the Trump administration rightfully and lawfully made the reductions in response to the "illegal" actions by previous U.S. presidents.

"President Trump walked back illegal and economically destructive actions by his predecessors and it's vital the people whose livelihoods are on the line — not just the well-to-do environmentalists who occasionally camp in the area — have the right to defend his actions," said David McDonald, staff attorney with the Mountain States Legal Foundation.

The foundation, a nonprofit public interest law firm, filed motions to intervene Tuesday on behalf of the counties asserting the rural, isolated and federal land-dominated regions have been negatively impacted by the monument designations.

"The designation of the Grand Staircase-Escalante National Monument has injured the local county governments and the small, rural communities they serve in multiple ways, both economically and culturally," the motion reads. "As local governments whose jurisdictions are almost entirely made up of land administered by federal agencies, much of the economic activity — and therefore the revenue such activity generates — within Kane and Garfield counties depends on the ability to access and make productive use of that federal land."

The same argument is made on behalf of San Juan County over the Bears Ears designation.

The lawsuits seeking to reverse Trump's actions last December were filed by multiple organizations, including the Wilderness Society, the Southern Utah Wilderness Alliance, the Navajo Nation and Utah Dine Bikeyah. Those groups argue that Trump's actions illegally overturned appropriate monument designations made by previous administrations.

Five cases have been consolidated into two and are pending in federal court in Washington, D.C. The Trump administration is urging the cases' transfer to Utah, where their outcome will have the most impact.

San Juan County Attorney Kendall Laws, in a signed declaration to the court, urged the boundary reductions at Bears Ears — now called Shash Jaa and Indian Creek units — be upheld by the court.

"Upholding President Trump's modification of the Bears Ears National Monument will prevent the sorts of job losses and other harms suffered by neighboring Kane and Garfield counties under the Grand Staircase-Escalante National Monument, safeguarding San Juan County's economy, community and culture," the document reads.

The filings point to a 2015 study that shows Garfield County has lost out on $9 million in economic output due to grazing restrictions that followed the monument's designation and was deprived of needed revenue through mining, logging and other activities.

Beyond economic harm, the filings argue the Antiquities Act was never intended to be used as a tool to set aside the amount of land at issue in Utah — 1.9 million acres at Grand Staircase-Escalante and Bears Ears at 1.35 million acres.

"Despite the Antiquities Act’s narrow language, millions of acres of federally controlled lands have been locked up by designation of national monuments. In recent years, designations have barely given lip service to the governing standards in the Antiquities Act, and courts have given significant deference to the president’s determination that an area contains objects of “historic or scientific interest," the document reads.

It adds that the deference, over the years, has been disconcerting.

"The courts’ construction of the Antiquities Act as allowing designation of virtually any federally controlled lands is particularly concerning given that the United States 'owns' 600 million acres of land, or about 28 percent of this nation."

Other parties are seeking to intervene in defense of the monument reductions, including the American Farm Bureau Federation and the Utah Farm Bureau.