Utica Auxiliary No. 3 is a privately owned rockfill dam located in Alpine County, California, along the North Fork Stanislaus River. Built in 1903 for hydroelectric power generation, the dam also serves purposes such as recreation and water supply. With a height of 10 feet and a storage capacity of 2,500 acre-feet, the dam's spillway type is uncontrolled, with a width of 91 feet. The dam has a low hazard potential and a moderate risk assessment rating.

Managed by the Federal Energy Regulatory Commission, Utica Auxiliary No. 3 undergoes state-regulated inspections and enforcement, ensuring its safety and compliance with regulations. The dam has a structural height of 9 feet and a hydraulic height of 9 feet, with a length of 91 feet and a surface area of 233.5 acres. Its maximum discharge capacity is 2,700 cfs, serving the surrounding area for water supply and recreational activities. With its historical significance and ongoing maintenance, Utica Auxiliary No. 3 plays a crucial role in the region's water resource management and climate resilience efforts.