Mary No. 2 is a privately owned earth dam located in Arvada, Wyoming, along the Arpan Draw river. Completed in 1973, this dam serves multiple purposes including fire protection, stock watering, and small fish pond maintenance. With a height of 22 feet and a length of 430 feet, Mary No. 2 has a storage capacity of 95 acre-feet and a surface area of 7 acres. Despite its low hazard potential and fair condition assessment, the dam is classified as having a moderate risk level (3), highlighting the importance of ongoing monitoring and maintenance.

Managed by the Wyoming State Engineer's Office, Mary No. 2 is subject to state regulation, permitting, inspection, and enforcement. The dam features an uncontrolled spillway with a width of 30 feet and one uncontrolled outlet gate. While the dam has not undergone any modifications in recent years, it is inspected every 5 years to ensure its structural integrity and safety. With its location in Johnson County, Wyoming, Mary No. 2 plays a crucial role in flood risk reduction in the area, demonstrating the essential role of dams in water resource management and climate resilience efforts.

Overall, Mary No. 2 stands as a vital infrastructure asset in Wyoming, providing essential services for fire protection, stock watering, and flood risk reduction. With its moderate risk level and fair condition assessment, ongoing monitoring and maintenance are crucial to ensure the safety and functionality of this earth dam. As water resource and climate enthusiasts, it is important to recognize the importance of dams like Mary No. 2 in managing water resources, protecting communities, and enhancing climate resilience in the face of changing environmental conditions.