MILLTOWN - Milltown Dam, a 100-year-old landmark that came to symbolize the economic prosperity and environmental destruction of Montana's mining industry, came down Friday.

The forces of man and nature combined - in the form of tons of water seeking the path of least resistance and a heavy equipment operator who dug out the last of a temporary earthen dike - to allow the Clark Fork and Blackfoot rivers to flow freely for the first time in a century.

Beneath sunny skies and snow-covered mountains, hundreds of people gathered to watch from the riverbanks and a bluff above Milltown Reservoir, which marks one end of the largest Superfund site in the nation. "I feel like an 8-year-old kid waiting for Christmas," said Chris Brick, staff scientist for the nonprofit Clark Fork Coalition.

Before the breaching, Sen. Max Baucus, Sen. Jon Tester and other officials told the crowd that the Milltown project represented Montana's shift from an extraction to a restoration economy, creating jobs that protect the environment and use the state's natural resources in sustainable ways rather than plundering them.

"We all know Montana is perfect, and today we are making it more perfect," Baucus said.

At noon, Gov. Brian Schweitzer shouted: "Let 'er run!"

And the rivers - starting as a trickle that became a torrent that became a muddy waterfall - poured through the channel where the dam's old powerhouse and north abutment were demolished in January.

Removal of the other half of the dam - made up of the spillway, radial gate and divider block - is slated to start this summer and will be complete next spring as part of the $120 million cleanup, restoration and redevelopment of the reservoir area paid for by the Atlantic Richfield Co., which bought the old Anaconda Copper Co.

Rather than a "blow-and-go" dam detonation that releases a river suddenly, the Milltown breaching was designed to let the water pressure slowly erode the earthen dike.

Working right up to breaching time, heavy equipment operators had scooped away most of the dike, dug a pilot channel, removed dewatering wells to allow underground seepage and partially closed the radial gate - measures meant to encourage the rivers to take their natural course.

At the governor's signal, the proverbial plug was pulled and the rivers, whose confluence is just above the dam, did the rest.

The initial 15-foot-wide gap widened under the water pressure, which slowly head-cut its way up through the breach and created a crumbling chasm.

Throughout the day and into the night, the dike's disintegration accelerated like a sand castle being washed away by a rising tide, sending timber beams, stumps, rocks and other debris downstream.

The river's thalweg - or the strongest current in the deepest part of the river - was expected to push through the channel and obliterate the remaining dike late Friday or early Saturday.

Federal, state and local officials, river advocates, construction workers and others cheered as the dam came down.

"This is a significant achievement that everyone can be proud of," said Matt Fein, Milltown project director for Envirocon, the Missoula-based contractor for the cleanup and dam removal.

"This is an incredibly important milestone," said Karen Knudsen, executive director of the Clark Fork Coalition, which campaigned for two decades to have the river cleaned up and the dam and contaminated sediment removed.

"This is what we've been working toward," said Peter Nielsen, environmental health supervisor in Missoula's City-County Health Department.

The breaching dropped the reservoir's water level another 14 feet and raised the downstream water level for several hours afterward, although the river rose less than expected because cool spring temperatures have slowed snowmelt.

The river's rise moved imperceptibly downstream, where people gathered along the riverbanks to watch, including a crowd gathered on the Higgins Avenue bridge. One man joked: "I'm waiting for a tsunami."

At the dam site, the water initially plunged 20 feet through the breach - the elevation difference above and below the dam - but that grade will flatten out as the rivers return to their natural levels.

Larger dams than Milltown have been removed, but few have been as complicated because of the copper, arsenic and other heavy metals contaminating sediments behind the dam.

The project is expected to have profound changes on the Clark Fork's physical, biological and chemical makeup as it readjusts to its natural state.

Full Story And Video: http://www.missoulian.com/articles/2008/03/29/news/top/news01.txt