Cox Hollow Number Two, also known as Twin Valley Lake at Governor Dodge State Park in Wisconsin, is a state-owned recreational dam on Mill Creek. Built in 1965 by the USDA NRCS, this earth dam stands at a height of 55 feet and has a hydraulic height of 37 feet, providing a storage capacity of 5,370 acre-feet. With a surface area of 152 acres and a drainage area of 13.9 square miles, the dam serves the primary purpose of recreation.

Despite its age, Cox Hollow Number Two is in fair condition with a high hazard potential, prompting regular inspections by the Wisconsin Department of Natural Resources. The dam's spillway is controlled with a width of 5 feet, and it has a maximum discharge capacity of 606 cubic feet per second. The risk assessment for the dam is categorized as very high, emphasizing the need for continued monitoring and maintenance to ensure public safety and water resource protection in the surrounding area.

For water resource and climate enthusiasts, Cox Hollow Number Two offers a fascinating glimpse into the intersection of human infrastructure and natural ecosystems. This recreational dam not only provides opportunities for outdoor activities but also serves as a vital component of the local watershed, contributing to flood control and water storage. As we continue to navigate the challenges of climate change, understanding and maintaining dams like Cox Hollow Number Two will be crucial in safeguarding our water resources for future generations.