Rhinedollar, also known as Ellery Lake, is a private hydroelectric dam located in Lee Vining, California. Completed in 1927, this Rockfill dam stands at a height of 18 feet and has a structural height of 17 feet. With a storage capacity of 749 acre-feet, Rhinedollar serves primarily for hydroelectric purposes and also offers recreational opportunities.

Managed by the Federal Energy Regulatory Commission, Rhinedollar is considered to have a high hazard potential due to its location and design. Despite its age, the dam undergoes regular state inspections and enforcement to ensure its safety and compliance with regulations. The dam's spillway is uncontrolled with a width of 38 feet, and it is located on Lee Vining Creek, a tributary in Mono County, California.

Water resource and climate enthusiasts will find Rhinedollar a fascinating structure to study, with its historical significance in California's hydroelectric development and its ongoing role in providing renewable energy. The dam's moderate risk assessment, combined with its unique design features and location, make it a valuable case study for understanding the intersection of water management, infrastructure, and environmental considerations in the face of changing climate conditions.