Washington • Senate Minority Whip Dick Durbin and 13 Democratic colleagues urged President Donald Trump not to change the boundaries of the Bears Ears or Grand Staircase-Escalante national monuments, saying whittling down the size of the designations could harm the resources and cultural sites they were meant to protect.

National monuments have preserved our country’s unique public lands, extraordinary history, and our common culture as a people,” the senators wrote in a letter Monday.

Interior Secretary Ryan Zinke, as ordered by Trump, has issued a review of national monument designations back to January 1996 and recommended trimming the Bears Ears and Grand Staircase-Escalante monuments but his report was vague on how much the president should reduce their boundaries.

Utah Gov. Gary Herbert suggested in a letter to Zinke that Bears Ears be shrunk to one-tenth of its current 1.35 million acre size, scaling the southeastern Utah monument down to about 120,000 acres surrounding Mule and Arch canyons west of Blanding, according to maps and other documents prepared by the governor’s office and obtained by The Salt Lake Tribune through records requests.

The Democratic senators said in their letter Monday that no boundaries should be changed and the administration should instead work to develop a management plan for the monument with the Bears Ears Advisory Committee, which was set up as part of the designation to include tribal leaders in decisions regarding the area.

We feel any changes to these monuments puts the resources and cultural sites they were created to protect at risk,” the senators wrote.

The Democrats also criticized Zinke’s review that said the Grand Staircase-Escalante designation had hindered cattle grazing when it has only reduced it by 1 percent and that it led to the closure of the Paria River Road when that road is outside the monument.

Durbin, of Illinois, is the sponsor of the America’s Red Rock Wilderness Act, legislation backed by the Southern Utah Wilderness Alliance and seeks to protect 9.2 million acres of public land in Utah.

Sen. Orrin Hatch, R-Utah, who asked Trump to seek a review of monuments, criticized the letter from Democrats.

“As was the case with President Obama‘s designation, this letter does not represent a single local official in San Juan County,” he said, referencing the county that includes Bears Ears. “We trust that the president’s decision, based on a fair, thorough, and inclusive review from Secretary Zinke, will take into account the letter and intent of the Antiquities Act, calling for the ’smallest area compatible with proper care and management of the objects to be protected.’”

Monday’s letter was co-signed by Sens. Tom Udall of New Mexico, Patty Murray of Washington, Martin Heinrich of New Mexico, Cory Booker of New Jersey, Patrick Leahy of Vermont, Brian Schatz of Hawaii, Al Franken of Minnesota, Debbie Stabenow of Michigan, Ron Wyden of Oregon, Jeff Merkley or Oregon, Tammy Baldwin of Wisconsin, Chris Van Hollen of Maryland, Richard Blumenthal of Connecticut, Tammy Duckworth of Illinois and Bernie Sanders of Vermont.