HELENA, Mont. -- President Donald Trump's Interior Department prevented Glacier National Park's superintendent from accompanying Facebook founder Mark Zuckerberg on a recent park tour to save money, not to mute criticism over climate change, a spokeswoman for the agency said Thursday.

Park superintendent Jeff Mow and U.S. Geological Survey ecologist Daniel Fagre had planned to accompany Zuckerberg last weekend, but Interior Department officials in Washington, D.C., decided to assign park rangers to the tour instead.

Zuckerberg, who has previously criticized Trump's decision to withdraw from the Paris climate decision, highlighted the effects of climate change on the park in a Facebook post.

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"In a couple of decades, there may not be any glaciers left in the park at all," he wrote.

Scientists predict Glacier National Park's glaciers will largely disappear by 2030.

Mow has participated in the park service's climate change response program and has given public presentations on how warming temperatures are affecting parks in Montana and Alaska, where he previously worked. Last year, Mow accompanied then-Interior Secretary Sally Jewell on a tour that emphasized climate change.

"We really have a bully pulpit to begin talking about climate change," he said of Glacier officials in a 2015 TEDx talk in Whitefish.

Fagre is a top scientist studying climate change. He told the Flathead Beacon that he had been scheduled to go on the Zuckerberg tour, and then was told without explanation that he couldn't participate.

A spokeswoman for Glacier National Park did not return a call for comment Thursday.

Interior Secretary Ryan Zinke's spokeswoman, Heather Swift, denied that the decision to pull Mow and Fagre from the tour was related to the climate change debate.

"It was about using government resources and tax dollars responsibly, especially at the height of busy season," she said.

So the agency assigned other park officials to Zuckerberg, and he was given "first-class treatment," Swift said.

Asked how much money the Interior Department saved by substituting park rangers for Mow and Fagre, Swift declined to provide an amount.

"Every tax dollar matters," she said.

The Washington Post first reported about Interior Department officials preventing Mow and Fagre from meeting with Zuckerberg.