Leprechaun Lake Dam, located in Mason County, Washington, is a privately owned structure that serves the primary purpose of recreation. Built in 1966, this earth dam stands at a hydraulic height of 13 feet and a structural height of 16 feet, with a length of 400 feet. The dam has a storage capacity of 86 acre-feet, with a normal storage level of 38 acre-feet, covering a surface area of 6.7 acres within its drainage area of 0.36 square miles along Tr-Cranberry Creek.

Despite its recreational focus, Leprechaun Lake Dam has been classified as having a high hazard potential, indicating the potential risks associated with its operation and maintenance. However, as of the last inspection in August 2020, the dam's condition was deemed satisfactory. The Washington Department of Ecology regulates and inspects the dam, ensuring its compliance with state requirements. With a notable hazard potential and a satisfactory condition assessment, Leprechaun Lake Dam stands as a crucial structure in the water resource management of the area, balancing recreation with the need for safety and compliance.