U.S. Senator Jon Tester on Friday sent a letter to President Donald Trump and Interior Secretary Ryan Zinke seeking clarification over a leaked memo suggesting the two may consider "disposing" federal public lands to help pay for infrastructure costs.

The leaked memo, obtained this week by Politico and Axios, includes a line calling for the “disposal of federal real property” to “improve the overall allocation of economic resources in infrastructure investment.”

Tester said he would resist any plan by the administration to sell or transfer the management of federal public lands to the states. In his letter, he likened the proposal to mortgaging the nation's conservation legacy for short-term gain.

“In Montana, our public lands are the backbone of our $7.1 billion outdoor recreation economy,” Tester said. “Selling off these resources would be a short-sighted budget gimmick that directly damages the outdoor heritage we leave for our kids and grandkids, and undercuts every aspect of our outdoor economy.”

In December, under strong criticism, Zinke was forced to defend Trump's decision to shrink two national monuments. In doing so, he called Patagonia's claims that Trump stole the land a lie, and said it was false that he and Trump intended to sell or transfer public lands to the states.

“Public lands are for public use and not for special interests,” Zinke said in December. “No land, not one square inch, has been transferred or sold.”

While the leaked memo is only a draft of an evolving proposal surrounding talks of a larger infrastructure plan and how to pay for it, it drew widespread criticism on Friday.

In a letter to Zinke, Business for Montana's Outdoors cited recent polls suggesting that 96 percent of Montanans believe the state's outdoor recreation economy is important to the state's overall economy. Nearly 33 percent of the state's acreage is designated as public land, which benefits families and residents of all incomes.

“We were deeply disturbed to learn that selling federal public lands is a suggested component of the administration's draft federal infrastructure plan,” wrote Marne Hayes, the organization's director. “We respectfully ask that you stand with your home state and work to ensure selling public lands is a non-starter for funding the administration's infrastructure initiative.”

Tester said the latest issue wasn't the first time Trump and Zinke have targeted Montana’s public lands. He said Trump released a budget last summer that slashed $339 million from the Land and Water Conservation Fund, which is used by hunters and anglers to increase public access to public lands.

“We need to address our nation’s vast infrastructure needs, and I look forward to working with both of you to get roads built, bridges repaired, schools and Internet service improved, and dams maintained,” Tester wrote in Friday's letter.

“But if we fund these efforts by selling off our public lands, we are mortgaging our nation’s conservation legacy. We are hamstringing our powerhouse outdoor economy. We are robbing the next generation of one of their best assets. I will never accept that.”