Kent's efforts as a conservationist were not exclusive of development and growth. The establishment of Muir Woods as a national monument coincided with the development of the Mt. Tamalpais & Muir Woods Railway as a popular tourist attraction, a business in which both Kent and his father had an interest in. In Congress, Kent was a key proponent of 1913 legislation creating the Hetch-Hetchy Reservoir, a stance that ultimately cost him his personal friendship with John Muir, who Kent would call "a man entirely without social sense."