Lake Letterkenny Dam, located in Franklin, Pennsylvania, was completed in 1945 and serves primarily for recreational purposes. Standing at 16 feet high and spanning 201 feet in length, this stone dam holds a maximum storage capacity of 60 acre-feet with a normal storage level of 48 acre-feet. The dam is situated in Letterkenny Township and regulates the flow of the TR Rocky Spring Branch.

Although the hazard potential of Lake Letterkenny Dam is undetermined and its condition is not rated, it remains a key feature in the region's water resource management. With a federal ownership status and no state regulation or permitting, this dam offers a picturesque setting for outdoor enthusiasts and climate enthusiasts alike. As the dam continues to provide recreational opportunities, it also stands as a reminder of the importance of sustainable water resource management in the face of changing climate patterns.

For water resource and climate enthusiasts, Lake Letterkenny Dam represents a blend of engineering ingenuity and natural beauty. With its historic construction and serene surroundings, this dam serves as a focal point for understanding the intersection of water management, recreational activities, and environmental stewardship. As we navigate the challenges of a changing climate, Lake Letterkenny Dam stands as a testament to the enduring value of protecting our water resources for future generations.