President Biden on Tuesday formally designated a new national monument, the fifth of his presidency, at the Grand Canyon and used his remarks in Arizona to tout the administration’s climate and environmental record.

Biden, speaking at Arizona’s Red Butte Airfield, formally designated the Baaj Nwaavjo I’tah Kukveni Grand Canyon National Monument.

The new monument protects just under 1 million acres, slightly under the 1.1 million acres called for by tribal leaders, who hold the area sacred. The area will be protected from all new uranium mining, extending a 20-year prohibition established in 2012 under the Obama administration.

“From time immemorial, more than a dozen tribal nations have lived, gathered, prayed on these lands, but some 100 years ago they were forced out,” Biden said. “That very act of preserving the Grand Canyon as a national park was used to deny indigenous people full access to their homelands, to the places where they hunted [and] gathered.”

Invoking the area’s history, the president also took a veiled shot at educational policies in Republican-governed states that critics have accused of glossing over atrocities such as chattel slavery.

“At a time when some seek to ban books and bury history, we’re making it clear that we can’t just choose to know only what we want to know,” Biden said. “We should learn everything that’s good, bad and the truth about who we are as a nation. That’s what great nations do, and we’re the greatest of all nations.” 

Biden also touted his environmental record, including the Inflation Reduction Act, the largest climate bill in U.S. history, which he signed into law just under a year ago.

“In my first year in office we protected more lands and waters than anyone since the 1960s,” the president said, referencing protections for areas such as Alaska’s Bristol Bay and Minnesota’s Boundary Waters as well as the restoration of national monument status for Utah’s Bears Ears and Grand Staircase-Escalante National Monuments. “Last year I signed the largest climate bill in not only the history of the United States, but in the history of the world… these historic measures put us on track to cut all American emissions in half by 2030, and we’re well on our way.”

Sen. Kyrsten Sinema (I-Ariz.), who vocally lobbied for the designation along with House Natural Resources Committee ranking member Raul Grijalva (D-Ariz.), praised the designation, saying in a statement “today’s designation is the product of hard work and relentless determination of thousands of Arizonans from diverse backgrounds and interests, including Arizona tribal communities, local leaders, conservationists, sportsmen, and many more — all with a shared passion for protecting Arizona’s air, land, and water for future generations.”

Both Sinema and Grijalva were present for the designation.

Shortly before Biden’s remarks, House Natural Resource Committee Chair Bruce Westerman (R-Ark.) and Oversight Subcommittee Chair Paul Gosar (R-Ariz.) asked for further information from the information on how the restrictions on uranium mining will affect energy security.

“The Committee is deeply concerned that the [Grand Canyon] National Monument and corresponding uranium withdrawal increases America’s reliance on foreign adversaries for minerals, threatening America’s energy, economic, and national security for generations to come,” they wrote.