“Overall, however, only about 5% of the entire United States—an area slightly larger than the state of California—is protected as wilderness. Because Alaska contains just over half of America's wilderness, only about 2.7% of the contiguous United States—an area about the size of Minnesota—is protected as wilderness.”
 

From The American Presidency Project, Proclamation 10248—National Wilderness Month, 2021:

“During National Wilderness Month, we affirm that our Nation's public lands and waters must be accessible to all Americans, we recognize that our lands and waters can revitalize the soul and solidify our respect for the natural wonders that surround us and the earth we share, and we recommit to their preservation and protection, today and for future generations.

“The Wilderness Act, signed into law by President Lyndon B. Johnson in 1964, opened a new chapter in American conservation by creating the National Wilderness Preservation System. The primary goal of the act is to preserve the places "where the earth and its community of life are untrammeled." Today, the National Wilderness Preservation System includes more than 800 wilderness areas spanning more than 111 million acres. These wilderness areas are located within national forests, parks, wildlife refuges, and conservation lands and waters. During the COVID-19 pandemic, many Americans turned to these areas for physical recreation, mental well-being, and inspiration, and our public lands and waters became places of healing and sanctuary.

“But our natural wonders are at risk. Now more than ever, we must come together to combat the climate crisis and unprecedented acceleration of species extinction, to protect and conserve our great outdoors before it is too late.”