The report, provided to CNN, suggests revising aspects of Bears Ears' boundaries but does not detail where those changes would be made.
In a memo to the President, Zinke says he has produced at "45-day interim report" on the national monument -- as is requested in the executive order Trump signed in April -- and will issue a "more detailed final report" later this year.
"As a result of the review ... I recommend that the Bear Ears National Monument boundary be revised through the use of appropriate authority," Zinke wrote.
The Interior secretary, who most recently was a Republican lawmaker from Montana, goes on to suggest some of Bears Ears be changed from a national monument to a national recreation area or national conservation area, a move that would alter rules governing the land. He also suggests working with Congress to enable Native American tribes to co-manage cultural areas.
"The Bears Ears National Monument contains some objects that are appropriate for protection under the act," Zinke wrote, referencing rock art and Native American ceremonial sites and dwellings. "However, having conducted the review ... I find that the Bear Ears National Monument does not fully conform with the policies set forth" in Trump's executive order.
The decision delays any certainty for Bears Ears, a 1.3-million-acre parcel of lands that includes world-class rock climbing, age-old cliff dwellings and land sacred to Pueblo Indians that Obama designated a monument in 2016.
Trump's executive order authorized Zinke to review federal lands designated by Presidents Bill Clinton, George W. Bush and Barack Obama, setting up a possibly historic decision that would make Trump the first president to shrink a national monument.
Because of public pressure from Republicans in Utah, Trump expedited the review of Bears Ears. But Monday's decision will now lump a final decision on the controversial national monument in with 27 other national monuments, including Grand Canyon-Parashant National Monument, Grand Staircase-Escalante National Monument and Basin and Range National Monument, as well as a host of Pacific Ocean monuments.
Zinke said on a call with reporters Monday that rescinding Bears Ear's status "was an option," but that he believes there are "some antiquities within the monument that deserve protecting."
An Interior Department spokesperson said that the report produced by Zinke and released Monday "is not a final plan within the recommendations" but complies with the executive order, which "directed a 45-day interim report" and did not require a final report.
Zinke visited Bear Ears in May, meeting with different stakeholders in the fight over Bears Ears, including a host of Native American tribes who have long viewed parts of the land sacred.
But local officials, including Republicans in Salt Lake City, have pushed the Trump administration to rescind national monument status for the land.
"We are not people who are trying to seek lots of riches. We are focused on a way of life. And we think that government overreach interferes with those connections that we have to the land," said Bruce Adams, a San Juan County commissioner.
As Zinke noted in his report, some residents in San Juan County worried that keeping Bears Ears a national monument would hurt their ability to use the land and give the federal government too much influence in their lives.
Phil Lyman, another county commissioner who met with Interior officials earlier this month, said he thinks the Trump administration would "like to (fully) rescind the monument just to test that ability to rescind a monument but beyond that."
Sen. Orrin Hatch, a Utah Republican, said Monday he was "encouraged" by Zinke's report and heralded the secretary's "thoughtful and inclusive" review.
But just as there has been a vocal push to de-list the monument, there has been an equally vocal opposition, made up of Native American tribes and environmental and conservation groups.
Jennifer Rokala, executive director of the conservation group Western Priorities, called the suggestions an "undeniable attack on our national monuments and America's public lands."
A number of groups have said they intend to sue the Trump administration if they rescind the national monument status.