The Glines Canyon Dam is located well inside Olympic National Park. It was built illegally, without required fish ladders among other things. It has violated the integrity of the Elwha River watershed for more than a century.
An Act of Congress (the Elwha River Restoration Act of 1992) has mandated its removal, along with another dam downstream (outside the park). It's currently scheduled to be removed in 2012.
Don't be hasty, guys.
Photo taken early March 2009 from the Griff Creek Trail.