Upper Monarch Lake, located in Mineral King, California, is a privately owned dam with a primary purpose of water supply. Built in 1905, this gravity-type dam stands at 22 feet tall and has a storage capacity of 314 acre-feet. The lake covers a surface area of 17 acres and is fed by the Efk Kaweah River, serving as a vital resource for hydroelectric power and water supply in the region.

Managed by the California Department of Water Resources, Upper Monarch Lake has a low hazard potential and is considered to be in satisfactory condition as of the last assessment in 2017. With state regulation, permitting, and inspection in place, the dam is equipped to handle any potential risks or emergencies. The surrounding area of Tulare County benefits from the controlled water flow and storage provided by this essential infrastructure.

As an integral part of the water resource management system in California, Upper Monarch Lake plays a crucial role in maintaining a stable water supply for the region. With its historical significance dating back over a century, this dam continues to serve as a reliable source of water for both domestic and industrial use, while also contributing to the overall climate resilience of the area.