In the wilderness of Washington state's Olympic National Park, hydraulic hammers chip away at the Glines Canyon Dam in the largest dam-removal project in U.S. history.
The grinding knocks off chunks of concrete, slowly removing the once-imposing 210-foot-tall (64-metre) structure, whose construction in 1927 on the Elwha River blocked one of the world's most prolific salmon runs.
Nine miles downstream, workers last month removed the 108-foot-tall (33-metre) Elwha Dam, built in 1913, allowing the river channel there to flow freely for the first time in nearly a century.