AUDIE CORNISH, HOST:
Two dams that block the migration of salmon are coming down in the largest dam removal in U.S. history. The dam sits on the Elwha River in the northwest corner of Washington state. They were built in the early 1900s to power nearby timber mills, but their power is no longer needed. From member station KUOW in Seattle, Ashley Ahearn reports that the removal is releasing a lot of debris but also creating new life.
ASHLEY AHEARN, BYLINE: Everything is fresh. That's my first impression. This is a new place. I'm walking on new earth that's been delivered from above the lower dam now, millions of cubic yards. I'm at the mouth of the Elwha catching up with Anne Shaffer, who is a tough lady to keep up with.
ANNE SHAFFER: And this is estuary, so this is - it's unvegetated, but this is definitely the habitat that juvenile fish need.
AHEARN: Anne Shaffer heads the Coastal Watershed Institute. She's standing with a group of volunteers in hip waders. Every month, they come out to these tidal pools with a large net.
SHAFFER: You ready?
(SOUNDBITE OF WATER SPLASHING)
SHAFFER: I got to find it.
UNIDENTIFIED WOMAN: Here it is.
SHAFFER: No, come on down.
UNIDENTIFIED WOMAN: There it is.
SHAFFER: Take this. Shake down as you go. Watch for fish.
AHEARN: The group gently works the net in a narrowing circle, corralling the fish into one place where they can count and measure them. The goal is to keep tabs on what kinds of fish are using this new habitat and how big they are before they head out to the open ocean.
UNIDENTIFIED WOMAN: Starry flounder, 150.
CHRIS BYRNES: Steelhead, 140, 147.
AHEARN: One of the volunteers is Chris Byrnes. He's a biologist with the Washington Department of Fish and Wildlife. He's cupping a tiny steelhead in his hands.
BYRNES: Do we have a camera? I'd like to get a picture of this one.
AHEARN: How come?
BYRNES: Because his fins are all eroded. He looks really roughed up.
AHEARN: All the sediment that's been released from above the dams is making life hard for fish right now.
BYRNES: And all the steelhead look this way. They look really kind of haggard.
AHEARN: But the muck and debris is doing wonders for their habitat, and that's good for the long-term recovery of salmon in this river. The sediment has posed some problems. It's clogged a local water treatment facility and temporarily shut down dam removal.
Mike McHenry is a fisheries habitat biologist with the Lower Elwha Klallam tribe. He's taking me to a place very few people have seen because it's been under water for a century.
MIKE MCHENRY: So we're going to head down here a ways, a quarter mile or so, and I'll get you out on the former reservoir surface.
AHEARN: We're about five miles from the mouth of the Elwha, just above where the lower of the two dams used to be. Not too long ago, this was a 250-acre reservoir. Now, it's a lifeless-looking mudflat with the Elwha flowing through it in braided, chocolaty channels. But McHenry says nature is already bouncing back.
MCHENRY: We've seen pools that have amphibians in them already. There's a lot of insect activity here. It's not a moonscape.
AHEARN: And it's only going to get greener. The Lower Elwha Klallam tribe is working with Olympic National Park to plant 400,000 native trees and shrubs here. McHenry leans over and brushes the leaves of a sturdy-looking plant, fighting its way out of the sandy soil.
MCHENRY: You know, we have thimbleberry here, which is a native shrub.
AHEARN: Loggers cleared this area 100 years ago. Then the dams were built, creating the reservoir. Now that the lower dam is completely removed, the lake that used to be here has drained away, and it's revealed giant ghostly stumps.
MCHENRY: Almost like they were cut yesterday, and there were some amazing trees that stood in this valley at one time.
AHEARN: We clamber up one of them. It's about 10 feet tall and wider than an eight-person dining room table. McHenry runs his fingers over the exposed tree rings, tracing back over the tree's growth history, hundreds of years. He says someday, there could be trees like this here again.
MCHENRY: You and I won't be around to witness it, but hopefully, our grandchildren and great grandchildren will be.
AHEARN: Dam removal is expected to continue later this summer. Both dams should be gone by the fall of 2014. For NPR News, I'm Ashley Ahearn. Transcript provided by NPR, Copyright NPR.