Fishtrap
Fishtrap is a rockfill dam located in Vilas County, Wisconsin, built in 1884. It carries a High hazard potential classification and has a fair condition assessment.
About Fishtrap
The primary purpose of Fishtrap is recreation. The dam creates a reservoir used for recreational activities such as fishing, boating, and swimming. The dam is owned by Wisconsin Department Of Natural Resources (state). It impounds the Manitowish near Boulder Junction.
The dam stands 14 feet tall and stretches 205 feet across, creates a reservoir covering 339 acres, has a maximum storage capacity of 14,468 acre-feet, and collects water from a drainage area of 59 square miles. Completed in 1884, the structure is over a century old.
This dam carries a high hazard potential classification, which means that a failure or uncontrolled release of water would likely cause loss of human life. This classification reflects the consequences of failure, not the likelihood — it indicates that people live or work in the area downstream. Its condition is rated fair — the dam has minor deficiencies that are being addressed or do not pose an immediate safety threat. An emergency action plan is in place for this dam. The most recent inspection on record was 09/06/2022.
Living Downstream
If you live or work downstream of this dam, consider taking these steps: learn your local evacuation routes, check whether your county emergency management office has a dam failure inundation map, and sign up for local emergency alerts. The Wisconsin dam safety program can provide more specific information about emergency planning for this structure.
Search for dams near your address to see all dams in your area with hazard classifications and safety data.
Location
| State | Wisconsin |
| County | Vilas |
| Nearest City | Boulder Junction |
| River/Stream | Manitowish |
| Coordinates | 46.11917, -89.60468 |
Physical Characteristics
| Dam Type | Rockfill |
| NID Height | 14 ft |
| Dam Height | 14 ft |
| Dam Length | 205 ft |
| Year Completed | 1884 (142 years old) |
Storage & Hydraulics
| NID Storage | 14,468 acre-ft |
| Max Storage | 14,468 acre-ft |
| Normal Storage | 6,993 acre-ft |
| Surface Area | 339 acres |
| Drainage Area | 59 sq mi |
| Max Discharge | 1,412 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Recreation |
| Owner | Wisconsin Department of Natural Resources |
| Owner Type | State |
| Hazard Classification | High |
| Condition Assessment | Fair |
| Last Inspection | 09/06/2022 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | WI00680 |
| Federal ID | WI00680 |
| More Info | State Dam Safety Program |