Historian-in-the-news Stephen Ambrose has pledged to donate $250,000 to help remove an aging dam near Missoula, Mont., at the confluence of the Clark and Blackfoot rivers, and clean up the 6.6 million cubic yards of contaminated sediment behind it. The Milltown Dam and its reservoir constitute the terminus of the nation’s largest Superfund site and the final resting place of decades of mine waste; the debate about what to do with the dam and the reservoir has been heated, with environmental groups in favor of removing both and restoring the riverbeds, at an estimated cost of $120 million. The company responsible for the cleanup, Atlantic Richfield, prefers a $20 million initiative to strengthen the dam and leave the sediment untouched. The U.S. EPA will issue a decision in the spring. Ambrose is siding with the greenies, calling the cleanup a "once-in-a-lifetime opportunity" to help the environment.

Grist thanks its sponsors. Become one.