An area south of Colt Mesa in Garfield County, Utah, on Oct. 11. The area is part of the Circle Cliffs region that was removed from Grand Staircase-Escalante National Monument. (Bonnie Jo Mount/The Washington Post)

The Interior Department’s Office of Inspector General has cleared Secretary Ryan Zinke in a probe of whether he redrew boundaries of a national monument in Utah to aid the financial interests of a Republican state lawmaker and stalwart supporter of President Trump.

In a Nov. 21 letter to Zinke’s deputy, David Bernhardt, Deputy Inspector General Mary Kendall wrote that her office “found no evidence” that the secretary or his aides changed the boundaries of Utah’s Grand Staircase-Escalante National Monument in an effort to help former Utah state representative Mike Noel, who serves as executive director of the Kane County Water Conservancy District. In December, Trump shrank the monument, established by Bill Clinton in 1996, by 46 percent based on Zinke’s recommendation.

Noel owns 40 acres that had been surrounded by the monument but now lies outside its boundaries. The new boundaries also would make it easier to construct the proposed Lake Powell Pipeline, which would deliver water to sites in Kane County that include Noel’s property. Earlier this year, Interior had proposed selling off 120 acres of federal land from the former monument that lay adjacent to some of Noel’s land holdings, but later reversed the plan.

“We found no evidence that Noel influenced the DOI’s proposed revisions to the [monument’s] boundaries, that Zinke or other DOI staff involved in the project were aware of Noel’s financial interest in the revised boundaries, or that they gave Noel any preferential treatment in the resulting proposed boundaries,” Kendall wrote.

The Interior Department and the inspector general’s office both declined to release the investigative report. In her letter, Kendall wrote that her office will provide the report to Congress “no sooner than 31 days” from Nov. 21, when it was shared with Zinke’s office.

The Associated Press first reported the inspector general’s conclusions Monday night.

The inspector general’s office still has at least two ongoing probes of the secretary, including one focused on his real estate dealings in Whitefish, Mont., and another regarding his decision to deny a permit to two Connecticut tribes who were hoping to jointly run a casino after MGM Resorts International lobbied against it.

Noel emailed Zinke about the effort to alter Grand Staircase-Escalante, according to emails released by Interior under the Freedom of Informational Act. But those emails do not make references to Noel’s land holdings. Noel also pushed to rename a Utah highway in honor of Trump but abandoned that effort in March after some of his fellow Republicans objected to the idea.

In a phone interview Tuesday, Noel blamed the Western Values Project, a liberal advocacy group, for spurring the inquiry by first questioning why his property was excluded from the monument.

“The investigation was done by an independent entity. I knew there wasn’t going to be anything to come out of it. I never spoke to anyone at Interior about my land," Noel said, adding that when it came to the final outcome, “I’m happy about it."

Western Values Project director Chris Saeger called on the inspector general’s office to release the full report “and let the public judge the merits of the findings.”

“Ryan Zinke just happened to recommend that President Trump exclude a Utah State Representative’s undisclosed 40-acre holding from the illegally reduced Grand Staircase-Escalante National Monument,” Saeger said in an email. “But the redrawn boundary, along with photos of Zinke and Noel together, seem to contradict whatever conclusions have been drawn from this leaked summary.”

Interior spokeswoman Heather Swift welcomed the watchdog’s conclusions.

“The report shows exactly what the secretary’s office has known all along — that the monument boundaries were adjusted in accordance with all rules, regulations and laws,” she said in an email. “This report is also the latest example of opponents and special interest groups ginning up fake and misleading stories, only to be proven false after expensive and time consuming inquiries by the IG’s office.”

Kendall’s spokeswoman Nancy DiPaolo declined to comment on the specifics of the report, noting it has not been publicly released, and defended the inquiry.

“The OIG opens investigations based on credible allegations and reports our findings objectively and independently,” DiPaolo said. “Any time or resources spent investigating conduct or activity that may be a violation of law, regulation or policy is a service to the public, Congress and the Department.”

Rep. Raúl M. Grijalva (Ariz.), the top Democrat on the House Natural Resources Committee, said in a statement he still intended to investigate the way Zinke and his colleague redrew the boundaries for Grand Staircase-Escalante and another Utah national monument, Bears Ears, next year.

“I have great respect for the inspector general, and I accept these findings, but Secretary Zinke should have known the people he listened to while destroying our national monuments had disqualifying conflicts of interest,” he said. “Should I chair the Natural Resources Committee in the next Congress, the process he and President Trump used to destroy Bears Ears and Grand Staircase-Escalante will be front and center in our oversight and investigations efforts. We need to know why they ignored overwhelming public expressions of support for both Bears Ears and Grand Staircase-Escalante, why they ignored Native American tribes throughout their decision-making, and why they removed protections on parcels of land with known mineral deposits.”