The removal of the Bonner Dam has environmentalists and recreationists rejoicing as the Blackfoot River moves one step closer to being restored to its historic free-flowing condition.

The ancient “rock and crib” dam, which was built in 1884 to serve the Bonner sawmill, washed out only a year later and has done so a number of times since.  A large ice floe in 1996 severely damaged the structure and its crest had fallen as much as two feet in areas.

Above: Historic photo of Bonner (Stimson) Dam. Below: Same stretch of river after dam removal. Photos courtesy of Missoula County.

The next step is the removal of the Milltown Dam, only a few miles downstream at the confluence of the Blackfoot and Clark Fork Rivers.  Local, state, and private parties involved in the dam removal project say the experience gained in removing the Bonner Dam will prove valuable in removing the Milltown Dam, which is also an ancient rock and crib structure—especially since the same company, Envirocon, is doing both jobs.

Once the Milltown Dam is gone, both the Blackfoot and Clark Fork Rivers will return to historic flow patterns and the confluence will be restored to natural conditions, with significant benefits both for river recreation and fisheries—especially for bull trout, which migrate up the Blackfoot to spawn in its headwater tributaries.

(March 2006)

Background: The Case for Removing the Milltown Dam