It's an annual treasure hunt full of surprises. For two weeks in November, the Army Corps of Engineers empties the Ballard Locks for cleaning, checking and prepping for another year underwater.

It starts as a rescue mission. Biologists rescue as much sea life as possible from the 100 year old engineering marvel. Crabs, sea stars, anemones, even a six-foot sturgeon sometimes get trapped below.

"Tryin' to rescue something that heavy, that big, get it over here and then crane it up and over these walls, you start to picture what might happen," says Operations Project Manager Nate McGowan.

"But they did a great job."

The lock chamber is 55 feet deep, 85 feet wide and 800 feet long. They've found everything down here from what you'd expect like glasses, cell phones and crab pots. But dentures, traffic cones and a surprising amount of barbeques have shown up as well.

The locks will remain dry until the middle of next week if you'd like to have a look.

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