Interior Secretary Ryan Zinke had a busy day on March 23, at least according to his official Twitter account. That day, he announced “Doggy Days” at the department, visited with staff at the Bureau of Reclamation, and met astronaut Jeff Williams. But Secretary Zinke’s day was even busier than his social media sharing lets on.

A calendar released under the Freedom of Information Act reveals several events Secretary Zinke didn’t highlight publicly, including a meeting with Idaho Gov. Butch Otter and an address to the board of directors of what appears to be the American Petroleum Institute (API). The API meeting was held at a notable location: President Trump’s Washington, D.C. hotel.

As the Washington Post’s Juliet Eilperin reported, Secretary Zinke’s calendars for March and April show he “spent much of his first two months in office meeting with energy and other industry groups.” Only the API meeting, however, was held at a venue that profits Secretary Zinke’s boss, President Trump, who still owns 77.5 percent of the hotel through a trust to which he is the sole beneficiary.

The API meeting is far from the only time a special interest group seeking to influence government policy has patronized President Trump’s private businesses. In April, for instance, the National Funeral Directors Association, which employs lobbyists, hosted a fundraiser for its political action committee at President Trump’s D.C. hotel. It is less common, however, for a Trump administration official to participate in such a gathering.

While the disclosure of the calendar sheds light on the existence of Secretary Zinke’s meeting with API, much about the meeting is still unknown. For instance, it is unknown how much the massive energy industry lobbying group spent to hold its board meeting at Trump International Hotel – Washington, D.C., because the Trump hotel does not list prices for meeting spaces on its website. The Washington Post, however, has previously reported that events at the D.C. hotel can cost more than $100,000 for organizers.

It is also unknown who from the oil and gas industry, exactly, attended the meeting with Secretary Zinke, who received $158,491 in campaign contributions from the industry during the 2016 election cycle. Unlike some of the other meetings listed on the secretary’s calendar (for example, an April 5 meeting with the Board of Directors of the National Alliance of Forest Owners) the calendar entry for the API meeting did not list attendees. The organization’s CEO-led board, however, includes representatives of major oil and gas companies.

API reported spending $2.69 million on lobbying in the first quarter of 2017, which included efforts to influence the Interior Department. In a statement to the Washington Post about meeting with Secretary Zinke, API President and Chief Executive Jack Gerard said “Interior is a critical agency for the natural gas and oil industry, regardless of who is in office.” Gerard added that Secretary Zinke “has been open to constructive dialogue and has shown a willingness to work with all stakeholders.” On the same day Secretary Zinke attended the API meeting, the Interior Department informed a federal court that it would be repealing an Obama-era rule regarding how federal royalties for fossil fuels are calculated. The next day, API issued a press release praising the decision.