Republican senators with competing bills to tackle the National Park Service’s $12 billion deferred maintenance backlog, which has been identified as a top priority for the Trump administration, reached a compromise Friday on a single measure.

The bill from Sens. Rob Portman, R-Ohio, and Lamar Alexander, R-Tenn., takes pieces from each of the senators’ previous bills to create a new trust fund to pay for national park improvements with revenue from energy production on federal lands.

With endorsements from Interior Secretary Ryan Zinke and leading parks advocacy groups such as the National Parks Conservation Association, the new legislation has momentum to move through Congress.

Co-sponsors include Sens. Mark Warner, D-Va., Angus King, I-Maine, Shelley Moore Capito, R-W.Va., and Cory Gardner, R-Colo.

“For more than a century, the National Park Service has been inspiring Americans to explore the natural beauty of our country,” Portman said in a statement. “But in order to keep that work going, we need to ensure that they have the right resources to maintain our national parks.”

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The legislation would establish the National Park Service Legacy Restoration Fund, an account within the federal treasury that would receive half the money from energy activities such as offshore oil and gas leasing or onshore solar panel development on public lands that do not have other federal financial obligations. The bill would cap the funding at $1.3 billion each year for five years to provide money specifically set aside for backlog maintenance.

The fund would establish mandatory spending for the projects, taking it out of the congressional appropriations process.

Under the bill, based on the receipts from federal land energy activities in fiscal 2016, the trust fund would see half of the $2.2 billion in unobligated money taken in from that fiscal year. And with the Interior Department’s “energy dominance” directive, that level is likely to be even higher in the coming fiscal years.

“Since my confirmation hearing, I’ve been adamant that we must address the nearly $12 billion maintenance backlog in our National Parks. I’m happy to see Senators Portman, Warner, King and Alexander teamed up to craft a very strong and historic bill to rebuild our national parks,” Zinke said in a statement. “This is not a Republican or Democrat issue, this is an American issue, and I think that the bipartisan body of lawmakers who put this bill forward is proof.”

Portman and Alexander had competing legislation to address the deferred maintenance backlog that eventually bubbled to the surface of a Capitol Hill rivalry during a Senate Energy and Natural Resources Committee oversight hearing in April.

Portman’s previous bill would have set an amount of funding from revenue paid to the government by companies extracting minerals and other resources from federal land. The bill was not the Trump administration’s preferred alternative.

Alexander’s bill, based on the proposal included in the Interior Department’s fiscal 2019 budget request, would have directed to a trust fund with mandatory spending half of the money derived from public land oil, gas, coal and renewable energy revenue above a 2018 baseline of $7.8 billion. The fear, though, was that proposal could never see money if the revenue did not go above the baseline.

“National parks bring people together and help bridge political party lines,” National Parks Conservation Association President Theresa Pierno said. “We commend the leadership of these park champions for their bill that makes a strong investment in our parks that they desperately need and deserve.”