When a government agency wants to attract as little public attention as possible to a new policy, it announces it on a Friday at 4 p.m. Eastern, a time at which many reporters are eyeing the clock in anticipation of happy hour. If the policy is really controversial, the agency will announce it just before a holiday. And if the policy is really, really controversial, the agency won’t even make an announcement, it will simply post it in the Federal Register—ideally between Christmas and New Year’s.

That’s what the Department of Interior (DOI) did on December 28, when it submitted proposed changes to how it will manage public requests under the Freedom of Information Act (FOIA). Such requests are one of the main tools journalists and advocacy groups use to learn details about government activities, and they can lead to kinds of revelations that ultimately forced Secretary of Interior Ryan Zinke out last month. Though he once said he planned to run “the most transparent Interior” in our lifetime, it was hardly surprising at this point that Zinke, who scribbled an inscrutable final goodbye with a chunky red pen last week, would approve an attempt to undercut Americans’ access to information about the workings of the DOI.

The proposed changes would give the agency almost unlimited discretion to deny FOIA requests. In the Federal Registry notice, the DOI says that in “light of the unprecedented surge in FOIA requests and litigation,” it would now deny “burdensome” or “vague” requests, or those that require “the bureau to locate, review, redact, or arrange for inspection of a vast quantity of material.”

What is a vast quantity of material? What is burdensome or vague? For the time being, it’s anyone’s guess. Because of the government shutdown, DOI hasn’t responded to requests from Outside or other media groups asking for clarification. “You can’t even submit a FOIA request while the government is shut down, but somehow they got this rule out,” says Jayson O’Neill, deputy director of the Western Values Project, a Montana-based conservation nonprofit. O’Neill believes this is the boldest step any government agency has ever taken to limit people’s access to public documents. “With this proposed change, that check on how our government works and the public’s ability to see how decisions are made will go away.”

To justify the rule change, DOI argues that from 2016 to 2018, requests to the department under the FOIA increased 30 percent, and that requests to the Office of the Secretary have increased 210 percent from 2015 levels. (The DOI did not respond to a request from Outside asking for more years to compare these figures with.)

The entire problem, though, might be one of DOI’s own making. Nada Culver, senior counsel with the Wilderness Society, says the department forces groups and media organizations to file requests by not handing over the kind of information previous administrations have readily shared. “Now they’re using [the surge in requests] as an excuse to further restrict disclosure,” she says. “I think part of the irony here is that it’s going to result in more requests, and more litigation.”

Another big factor, of course, is that Zinke has faced unprecedented 18 federal investigations—a fact that was sure to spur a lot of FOIA filings. Many of them have been fruitful. After the administration shrunk Bears Ears and Grand Staircase-Escalante national monuments, requests led to the discovery that the DOI had tailored its reports to emphasize the benefits of extractive industries over tourism. Other requests revealed a possible conflict of interest violation that linked Zinke to a real estate deal with oil-services behemoth Halliburton. That news prompted the DOI’s internal watchdog to open an investigation. Now, there are rumors of a criminal inquiry.

Almost as concerning as the proposed rule changes is the person Zinke recently appointed to be the Interior’s Chief FOIA Officer. The job typically goes to a career employee, someone removed from politics. In November, though, Zinke quietly named former Koch brothers adviser Daniel Jorjani. One of the first groups to notice the switch, several weeks later, was the Center for Biological Diversity. “With a Koch crony in charge of records requests, the department will work in darkness,” the group’s government attorney, Meg Townsend, stated in a press release. “Public records that might shame Zinke or big polluters will be covered up.”

So far, that seems prescient. Jorjani authored the FOIA changes.

The fact of the matter is that if the changes goes through—lawsuits could hold them up—it will be impossible to measure the impact because we’ll never know what might have been uncovered if the DOI had continued to respect public requests for information. One can imagine how, under the new rules, journalists would never have learned about the potential Halliburton deal. And in that reality, maybe Zinke wouldn't have resigned.

The public has until January 28 to comment on the change. But with just 189 comments received as of the morning of January 7, the DOI’s effort to push this out quietly seems to be working.