Hillary Clinton (Charlie Neibergall/AP)

More than a century ago, John Muir immersed himself in the wilderness of the Sierra Nevada mountains. In the journals he kept on his travels, Muir observed that “Most people are on the world, not in it.” He worried humanity had lost touch with our place in nature, and he hoped to inspire us to find it.

In the years that followed, his message began to break through. Leaders of American industry and society came to agree that public lands and waterways had to be held in sacred trust. Muir even went camping with President Teddy Roosevelt in the Yosemite Valley, who then set off a golden age of conservation.