Harold Hamm, the billionaire Oklahoma oil tycoon and Giving Pledge signatory, has donated $50 million for the planned Theodore Roosevelt Presidential Library in Medora, North Dakota, the Bismarck Tribune reports.

The gift was announced by North Dakota governor Doug Burgum during his annual address to the state’s legislative assembly and will advance the construction and development of the library in honor of the 26th president of the United States, who ranched and hunted in the Medora Badlands in the 1880s. In 2019, the state legislature approved a $50 million operations endowment for the library, made available in 2020 after $100 million was raised from private sources. The project is estimated to cost between $400 million and $900 million.

According to the Bismarck Tribune, Hamm—who began his career in the North Dakota oil fields—has previously made donations in the state, including $1.8 million to the North Dakota Heritage Center & State Museum in Bismarck, $10 million to the University of North Dakota in Grand Forks, and $12 million to the University of Mary in Bismarck.

“We invest in big ideas that are built to last,” said Hamm. “The Theodore Roosevelt Presidential Library will inspire Americans for centuries not decades….It is an honor to support this ambitious vision, which will perpetuate TR’s legacy and bring visitors from around the world to the Badlands for generations to come.”

(Photo credit: Library of Congress/Pach Brothers)