Sheridan is a privately owned dam located in Island Park Reservoir, Idaho, along the East Fork Big Lost River and Big Lost River. Built in 1873, this earth dam stands at 22.4 meters high with a hydraulic height of 18.4 meters. With a storage capacity of 2105 acre-feet and a surface area of 286 acres, Sheridan plays a crucial role in water resource management in the region.

Despite its historical significance, Sheridan faces significant risk due to its poor condition assessment and the potential for significant hazards. With a very high risk rating, this dam requires immediate attention and maintenance to ensure its structural integrity and the safety of surrounding communities. The dam features a controlled spillway type with slide gates for water release, but there are no locks associated with the structure.

It is essential for water resource and climate enthusiasts to monitor the condition of Sheridan closely, as its poor state and high risk rating pose a threat to the local ecosystem and water supply. With state regulations, permitting, inspection, and enforcement in place, efforts must be made to address the dam's maintenance needs and ensure its long-term sustainability. A collaborative approach involving various agencies and stakeholders is necessary to protect this vital water resource in the Idaho region.