Upper Mayville, located in Mayville, Wisconsin, is a local government-owned dam on the East Branch Rock River with a primary purpose of recreation. Built in 1848, this earth dam stands at 15 feet high and spans 200 feet in length, providing a storage capacity of 300 acre-feet and a surface area of 41 acres. With a low hazard potential and a satisfactory condition assessment, Upper Mayville is regularly inspected, with the last inspection taking place in September 2011.

The dam features a controlled spillway and has a maximum discharge capacity of 4,400 cubic feet per second. While the risk assessment for Upper Mayville is classified as very high, it has been assigned a DSAC rating of 1, indicating proactive risk management measures are in place. Despite being modified in 1946 and 2011, the dam has maintained its structural integrity and continues to serve as a vital recreational resource for the community. With its picturesque location and historical significance, Upper Mayville is a must-visit destination for water resource and climate enthusiasts looking to explore the intersection of nature and infrastructure.