Secretary of the Interior Ryan Zinke on Thursday reaffirmed the status of two of the 27 national monuments under federal review.

Zinke, who has not yet said whether he would recommend changing the designation of Maine’s national monument, will advise President Donald Trump to leave untouched Craters of the Moon National Monument & Preserve in Idaho and Hanford Reach National Monument in Washington state. His review is due on Aug. 24.

“When the President and I began the monument review process we absolutely realized that not all monuments are the same and that not all monuments would require modifications,” Zinke said in a statement.

Zinke visited Katahdin Woods and Waters National Monument for two days last month and gave mixed signals about what he would recommend.

He hinted support for retaining federal control of Katahdin Woods on June 14 and floated the idea of seeking legislation to turn it into a national park the next day. He told a senate subcommittee on June 20 that monument friends and foes will be “enthusiastic” about his recommendation.

Zinke called Craters “a living timeline of the geologic history of our land” and said Hanford Reach offers “some of the best fishing and bird hunting around.”

Trump ordered the review in April to determine whether Presidents Bill Clinton and Barack Obama overstepped their authority when they designated the 27 monuments. Maine’s was created in August 2016.

It is unclear whether presidents have the legal power to rescind monument designations. Congress clearly can do that through legislation.