National Park Service

The Sonoran Desert stretches from central Arizona into Mexico.

Monday is the final day for public comment about dozens of national monuments under review by the federal government. Four of the monuments, Ironwood Forest, Sonoran Desert, Vermillion Cliffs and the million-acre Grand Canyon/Parshant region, are in Arizona.

Ani Kame'-enui with the National Parks Conservation Association believes President Donald Trump's executive order to review the monuments amounts to an attack on the Antiquities Act, which grants the president the power to protect sites on land already owned by the federal government.

"The Antiquities Act is really responsible for creating some of our best known national parks whether it's the Statue of Liberty or the Grand Canyon. So any effort to undermine this act or question the sites that it has honored and protected is really an insult to our national heritage," said Kame'-enui.

In April, President Trump directed Secretary of the Interior Ryan Zinke to review 27 monuments of more than 100,000 acres created since 1996.

Zinke, who will review the comments and make a recommendation later this summer, has already endorsed shrinking the boundaries of Bears Ears National Monument in Utah, established by President Barack Obama last year.

As of last week, the Interior Department had received over 1 million comments to regulations.gov.