Estabrook Falls Fish Passage

Bedrock Removed to Create a Passing Lane for Fish

The Estabrook Falls Fish Passage Project was an important effort to help native fish, like northern pike and lake sturgeon, move upstream to reach vital spawning and nursery habitat. These native fish were weak jumpers and could not make it past barriers like Estabrook Falls, which was not a natural waterfall but a leftover feature from historic bedrock mining. While fish could occasionally pass during very high river flows, the falls typically acted as a significant barrier and was the largest remaining obstacle to fish passage in the lower Milwaukee River.

In 2025, crews removed bedrock in select locations to allow native fish to pass. This created a new pathway that allowed fish to safely move upstream past the falls—something that had not been consistently possible for over 100 years. As a result, fish were able to travel farther upstream than they had in generations, reaching over 60 miles of river and tributaries and accessing 2,400 acres of wetlands for spawning and feeding. The project ultimately improved year-round fish movement and supported a healthier, more connected river system.