Fishtrap, located in Vilas County, Wisconsin, is a rockfill dam built in 1884 on the Manitowish River. With a height of 13.8 feet and a storage capacity of 14,468 acre-feet, Fishtrap primarily serves as a recreational area, offering activities like fishing and boating. The dam has a spillway width of 47 feet and a maximum discharge of 1,412 cubic feet per second, making it a significant structure in managing water resources in the area.

Despite its age, Fishtrap has undergone modifications in 1935 and 2019 to ensure its continued functionality. The dam is under the jurisdiction of the Wisconsin Department of Natural Resources (WIDNR) and is subject to regular inspections, with a hazard potential rating of "High" and a condition assessment of "Fair". The risk assessment for Fishtrap is moderate, indicating a need for ongoing monitoring and management to mitigate potential hazards and ensure the safety and integrity of the dam for both recreational and water resource purposes. With its historical significance and role in water management, Fishtrap is a key feature in the landscape of Boulder Junction and a focal point for water resource and climate enthusiasts in the area.