BISMARCK, N.D. (AP) — Oil industry giant Harold Hamm will contribute $50 million to the planned Theodore Roosevelt Presidential Library in North Dakota, Gov. Doug Burgum said Tuesday.

The governor announced Hamm’s donation in his State of the State address to the Legislature, the Bismarck Tribune reported.

The library will honor the 26th U.S. president, who was born in New York, and later ranched and hunted in the Medora Badlands of western North Dakota in the 1880s. It will be built on 90 acres of former U.S. Forest Service land near Medora, outside Theodore Roosevelt National Park.

Hamm founded Continental Resources and pioneered horizontal drilling in North Dakota’s oil-rich Bakken region. His net worth is estimated at $27 billion, according to Forbes.

Library CEO Ed O’Keefe declined to say how much the library project has raised in total, or how much it will cost by completion, but he called Hamm's gift “a game-changer.”

“We invest in big ideas that are built to last," Hamm said in a statement. “The Theodore Roosevelt Presidential Library will inspire Americans for centuries not decades.”

The 2019 Legislature approved a $50 million endowment for library operations that was contingent on $100 million in private donations, which organizers reached in 2020. Rob and Melani Walton, of the Walmart fortune, donated $15 million earlier.

Organizers plan to hold a ceremonial event to break ground on construction before the end of this year. The library is hoping to hold its grand opening on July 4, 2026.