"Greater Canyonlands is one of our nation's most stunning, wild and unique landscapes," the letter reads. "It should be protected permanently for the benefit and education of future generations."
The Navajo Nation has also lobbied the Interior Department to create a national monument in the area, since it contains some areas they consider sacred.
Sen. Orrin Hatch, R-Utah, said it wasn't surprising that Democratic senators want the monument, but said: "It is discouraging that they want President Obama to abuse that authority on lands in a state they don't live in or represent in the Senate."
The 1906 Antiquities Act allows presidents to unilaterally create national monuments and Obama has used it a handful of times. In his State of the Union address this year, he promised additional ones.
"I'll use my authority," he said, "to protect more of our pristine federal lands for future generations."
Rep. Rob Bishop, R-Utah, doesn't want to see that happen. He pushed legislation this year that would require a thorough environmental study of any new national monument and would limit the president's power by capping it at one monument per state each four-year term.
The House passed Bishop's bill but the Senate hasn't taken it up.
Bishop has also convened a working group of county officials, energy companies and environmental organization in hope of striking a compromise, setting aside certain lands for energy development and others as wilderness. That effort, made in part to avoid a new national monument, is ongoing.
None of Utah's members of Congress has supported the creation of a Greater Canyonlands National Monument. They have argued instead that the president shouldn't create a new monument without local support.
That's what happened with the last national monument designated in Utah. President Bill Clinton shocked Utah officials when he announced the creation of the Grand Staircase-Escalante National Monument in 1996.
In a speech on the Senate floor Hatch equated that move to the Japanese attack on Pearl Harbor.
"This massive proclamation came completely without notice to the public," Hatch said. "The biggest presidential land set-aside in almost 20 years was a sneak attack."
The senators who signed the letter are Durbin, Boxer, Warren, Tammy Baldwin, D-Wisc., Richard Blumenthal, D-Conn., Sherrod Brown, D-Ohio, Tom Harkin, D-Iowa, Ed Markey, D-Mass., Robert Menendez, D-N.J., Patty Murray, D-Wash., Bernie Sanders, I-Vt., Brian Schatz, D-Hawaii, Debbie Stabenow, D-Mich., and Sheldon Whitehouse, D-R.I.