Mcmahon is a private earth dam located in Snelling, California, along Maxwell Creek. Built in 1957, this dam serves primarily for water supply, with a storage capacity of 520 acre-feet. It stands at a height of 52 feet and has a hydraulic height of 42 feet, making it a crucial structure for irrigation and water supply in the area.

Managed by the California Department of Water Resources, Mcmahon is regulated, permitted, inspected, and enforced by state agencies to ensure its safety and compliance with regulations. Despite its low hazard potential, the dam is regularly assessed and deemed to be in satisfactory condition. The last inspection in August 2019 confirmed its structural integrity, making it a reliable resource for water management and climate resilience in Mariposa County.

With its strategic location and vital role in water supply, Mcmahon represents a valuable asset for the community and the environment. As a key structure along Maxwell Creek, this dam not only provides essential water resources but also contributes to the overall sustainability and resilience of the region. Its satisfactory condition and low hazard potential underscore the importance of proper maintenance and monitoring to ensure its continued functionality and safety for years to come.