Answer:
John Muir encouraged President Theodore Roosevelt to put the Yosemite Valley under federal protection.
Explanation:
In 1903, in Yosemite, Roosevelt and Muir camped three nights among redwoods, woke up covered by a thin layer of snow, visited the Grand Captain and photographed at Glacier Point. For the National Park System this trip can be considered the most significant in the history of conservation.
Upon his return, Roosevelt made a series of decisions that seem to confirm it: in 1906 he signed a federal law so that Yosemite Valley and Mariposa Grove become part of Yosemite National Park, after a 17-year campaign by Muir and the Sierra Club, while declaring Petrified Forest, in Arizona, national park. Two years later he proclaimed the Muir Woods National Monument, a forest of elegant sequoia trees north of San Francisco, in honor of his Yosemite guide.
