BRADLEY, Me. -- Under a bright sky here, a convoy of heavy equipment rolled onto the bed of the Penobscot River on Monday to smash the Great Works Dam, a barrier that has blocked the river for nearly two centuries.
Before the destruction began, a tribal elder from the Penobscot Indian Nation used an eagle wing to fan smoke from a smoldering smudge of sage, tobacco and sweet grass over the crowd that had gathered to watch.
"Today signifies the most important conservation project in our 10,000-year history on this great river that we share a name with, and that has provided for our very existence," said the tribal chief, Kirk Francis.
The Penobscot River's once-abundant runs of salmon, shad, sturgeon, alewives, eels and smelt were nearly wiped out because for years the dams -- there are three in the river's first 10 miles alone -- impeded migrations to their spawning grounds. "Returning these species of fish to their historic habitat, we will see the river continue to come back to life in a major way," Mr. Francis said.
The long-delayed start of the dam-removal project is expected to end years of rancor and uncertainty. Plans to dismantle the dams began in 1999, when PPL Corporation, a power company, bought a series of Penobscot River dams from Bangor Hydro Electric Company. Wanting to avoid the conflicts that had accompanied dam-licensing efforts on the river, PPL began negotiating with the Penobscot Indian Nation and several conservation groups. They agreed on a deal that allowed PPL to sell several dams for removal or decommissioning, while increasing power generation at six other dams to offset the power losses.
The Federal Energy Regulatory Commission signed off on the agreement in 2004.
"The backdrop for the negotiations was total rancor on the river, over every individual dam relicensing," said Laura Rose Day, executive director of the Penobscot River Restoration Trust, a coalition formed by the tribe and conservation groups to buy and remove the dams.
Still, not an ounce of concrete had been touched until Monday. First, the trust had to raise $25 million to buy the dams from PPL, which it accomplished in 2010. Then it had to raise more money to take them down.
The Penobscot still has the nation's largest run of Atlantic salmon, which are listed as endangered under the Endangered Species Act. The fish are trapped at a fish ladder on the Veazie Dam, between the Great Works Dam and the ocean, and trucked upriver or to hatcheries. More than 3,000 salmon returned to the river in 2011, the largest run in 25 years, but historic runs were most likely 20 times that size.
Project supporters say the endangered salmon will get a boost when the dams come down, but other fish may benefit even more. Pat Keliher, commissioner of the Maine Department of Marine Resources, said migratory fish rebounded quickly on Maine's Kennebec River when the Edwards Dam was removed in 1999. That river now has a run of more than three million alewives.
Mr. Keliher said the Penobscot also has great potential for shad. "Shad can provide a great angling opportunity, and our biologists predict that over time this river could support a run of over one million fish," he said.
It may be a few months before the river flows freely here. The next steps will come when the Veazie Dam, at the head of tide near Bangor, comes down, perhaps as soon as July 2013. Meanwhile, Black Bear Hydro, the power company that bought PPL's Penobscot interests in 2009, will build a fish lift at the Milford Dam, which will then be the first barrier to migrating fish. And farther upriver, the trust will decommission and build a bypass around the Howland Dam.
In all, supporters say, Atlantic salmon and other fish will have improved access to more than 1,000 miles of river.
The total cost of buying and removing the dams will be $62 million, a nearly even split between private and public money. At the river on Monday, Interior Secretary Ken Salazar announced $2.5 million in new federal support from the federal Fish and Wildlife Service. The National Oceanic and Atmospheric Administration contributed an additional $1 million.
"For those who say we have to choose between taking care of our planet and conservation on the one hand, and jobs on the other hand, let's all remind them that it's a false choice," Mr. Salazar said. "And we're proving it right here today on the Penobscot River."
This article originally appeared in The New York Times.