Answer:
Muir; Pinchot
Explanation:
John Muir was well known for his love for the natural environment and has made many quotes about the beauty of nature, including the first quote mentioned in the question "We should maintain the environment in its most natural state as if we hadn't been here at all." He was born in 1838 and died in 1914.
Gifford Pinchot was also well known for his attachment to nature, he however, believed that humanity should use natures resources to our advantage. He was born in 1865 and died in 1946.