First Elwha and Glines Canyon, and now Condit: The three largest dam removals ever in the country will be under way in Washington state, when contractors detonate 800 pounds of dynamite and blast the White Salmon River free.

About 1,000 U.S. dams have been removed since 1912, according to the advocacy nonprofit American Rivers. But most have been small dams, many less than 20 feet high. Glines Canyon towers at 210 feet,which was removed last month, the Elwha was at 108 and Condit is 125 feet tall.

Taking out Condit Dam is expected to create 14 miles of salmon habitat and 33 new miles of habitat for steelhead. Salmon already have wasted no time digging nests in the upper reaches of the river, where biologists hand-carried 679 adult tule fall chinook last month, to start a new generation.