Mclellan, located in Coconino, Arizona, is a privately owned gravity dam on Johnson Canyon, built in 1907 for the primary purpose of serving as a Fish and Wildlife Pond. With a height of 21 feet and a length of 293 feet, this structure has a storage capacity of 110 acre-feet and a surface area of 19 acres. The dam is regulated by the Arizona Department of Water Resources, with state permitting, inspection, and enforcement in place to ensure its safety and functionality.

Despite being categorized as having a low hazard potential, Mclellan is considered to have a moderate risk level (3) based on a risk assessment. The dam's condition assessment is currently marked as "Not Rated", with the last inspection conducted in September 2019. The spillway, which is uncontrolled, has a width of 120 feet. While Mclellan does not have associated locks or outlet gates, it remains an important structure for water resource management in the area, supporting wildlife habitats and contributing to the local ecosystem in Masonry #2 Dam.

Overall, Mclellan plays a vital role in maintaining the ecological balance of Johnson Canyon and the surrounding areas in Arizona. Its historical significance, combined with its functionality as a Fish and Wildlife Pond, highlights the importance of proper regulation and maintenance to ensure the safety and sustainability of this gravity dam for future generations of water resource and climate enthusiasts to appreciate and enjoy.