Theodore Roosevelt is often considered the "conservationist president."
"Conservation increasingly became one of Roosevelt's main concerns. After becoming president in 1901, Roosevelt used his authority to protect wildlife and public lands by creating the United States Forest Service (USFS) and establishing 150 national forests, 51 federal bird reserves, 4 national game preserves, 5 national parks, and 18 national monuments by enabling the 1906 American Antiquities Act. During his presidency,Theodore Roosevelt protected approximately 230 million acres of public land."
"Today, the legacy of Theodore Roosevelt is found across the country. There are six national park sites dedicated, in part or whole, to our conservationist president. You can find more information about these places under Theodore Roosevelt related websites."
https://www.nps.gov/thro/learn/historyculture/theodore-roosevelt-and-conservation.htm
