Mcswain, a hydroelectric dam located in Mariposa, California, is a public utility owned and regulated by the state of California. Completed in 1966, this rockfill dam stands at a height of 97 feet and has a maximum storage capacity of 9730 acre-feet. With its primary purpose being hydroelectric power generation, Mcswain also serves irrigation and recreation purposes, making it a versatile water resource in the region.

Managed by the Federal Energy Regulatory Commission, Mcswain boasts a spillway width of 625 feet and a maximum discharge capacity of 250,000 cubic feet per second. Its hazard potential is classified as high, with a moderate risk assessment score of 3. Despite its condition assessment being labeled as not available, the dam is regularly inspected, with the last inspection conducted in September 2020. The emergency action plan for Mcswain was last revised in January 2021, ensuring that necessary measures are in place to mitigate any potential risks associated with the dam.

In the picturesque setting along the Merced River, Mcswain not only provides essential water resources but also contributes to the local economy and recreational activities. With its strategic location and robust infrastructure, this dam continues to play a vital role in water management and power generation in the region, while adhering to strict regulatory standards set by state and federal agencies.