The construction of O'Shaughnessy Dam in Yosemite’s Hetch Hetchy Valley, authorized by the Raker Act of 1913, sparked a national debate over a city’s water rights versus federal environmental responsibilities to protect public lands within national parks. Although preservationists like John Muir and the Sierra Club fought to preserve Hetch Hetchy Valley, San Francisco successfully secured municipal water rights by damming Hetch Hetchy. Ultimately, the Hetch Hetchy controversy influenced the modern conservation movement and pushed congress to establish the National Park Service in 1916, which manages parks through scientific methods and partnerships with other organizations. The NPS focuses on utilizing and conserving natural resources and public lands wisely for future generations, balancing the right to clean water with the responsibility of protecting Earth’s natural wonders.