 John Muir was a Scottish @-@ born American naturalist and explorer . It was because of Muir that many National Parks were left untouched , such as Yosemite Valley National Park . One of the most significant camping trips Muir took was in 1903 with then president Theodore Roosevelt . This trip persuaded Roosevelt to return " Yosemite Valley and Mariposa Grove to federal protection as part of Yosemite National Park " . 
