With the public comment period ending Monday, there are just hours left for the public to weigh in on President Donald Trump's order that threatens protections of 27 national monuments designated since 1996.

"These monuments were protected by presidents from both parties for good reason," said Randi Spivak, director of the Center for Biological Diversity's public lands program. "Their natural beauty and scientific and cultural importance is indisputable, but Trump and his corporate friends claim to know better. Sadly it's just their greed talking."

Trump's executive order, issued in April, called for Interior Secretary Ryan Zinke to conduct a review of designations or expansions made by the last three presidents using executive powers under the Antiquities Act of every monument larger than 100,00 acres "or where the Secretary determines that the designation or expansion was made without adequate public outreach and coordination with relevant stakeholders."

Among the currently designated areas (pdf) under review are Bears Ears National Monument and Grand Staircase-Escalante in Utah; the Mojave Trails in California; and Papahānaumokuākea Marine National Monument in Hawaii.

The order suggested that the review could open the possibility of fossil fuel drilling. It states: "Monument designations that result from a lack of public outreach and proper coordination with State, tribal, and local officials and other relevant stakeholders may also create barriers to achieving energy independence, restrict public access to and use of Federal lands, burden State, tribal, and local governments, and otherwise curtail economic growth."

As such, Lukas Ross, climate and energy campaigner with Friends of the Earth, warned: "In his first hundred days in office Trump is determined to turn our public lands and waters into energy sacrifice zones."

According to Zinke (who's earned a 4 percent lifetime score from the League of Conservation Voters), the review of the designations is to see if they should be "rescinded, resized, or modified in order to better benefit our public lands."

Opposition has poured in since the review was announced.

As of this writing over 1.3 million comments have been submitted. And in a letter sent in may to Trump, Zinke, and Commerce Secretary Wilbur Ross, 450 diverse organizations representing millions of people wrote to express their concern, stating that they "view an attack on any one national monument as an attack on them all."

The coalition argued that "an attempt to undermine protections for these uniquely American places would not only rob the American people of our shared heritage but establish a dangerous precedent that we can no longer trust that park or monument can be considered fully safeguarded for future generations."

To submit a comment online, go to regulations.gov and search DOI-2017-0002.