Thomas A. Edison and his team pioneered the development of hydroelectric power generation in California's Sierra Nevada region in the early 1900s. Edison's power plants harnessed the energy of the San Joaquin River, providing electricity to the growing city of Los Angeles. To ensure water flow, Edison built dams and reservoirs, including Florence Lake and Shaver Lake. The snowpack in the Sierra Nevada mountains is a critical source of water for California, and Edison's hydroelectric facilities helped to manage this resource. The company also played a role in agricultural irrigation, with the San Joaquin River providing water to farmers in the Central Valley. Today, the area around Edison's hydroelectric plants is popular for recreational activities such as fishing and camping.