Rescue crews are relying on high tech sensors and heavy equipment in the effort to find people buried in the Oso mudslide, but officials say search dogs have proven to be their most effective tool so far.

“The dogs are the ones that are pinpointing a particular area to look. We’re looking and that’s how we’re finding people,” said Snohomish County District 21 Fire Chief Travis Hots.

A number of teams from Redmond-based Northwest Disaster Search Dogs are among those combing through the massive debris field. They’ve traveled to such disasters as the World Trade Center collapse, Hurricane Katrina, and other catastrophes. But the search through the mudflow that buried an entire community and killed at least 24 people is unlike anything they’ve ever faced.

“This is among the worst disasters we’ve ever seen,” says coordinator Lisa Bishop. She says officials have assigned them specific areas to work throughout the area. Some of the dogs are trained to search for survivors, others for cadavers.

“They’ll smell it if there’s a live individual there or human remains there. If it’s not completely encased in mud where no scent is escaping, they will be able to detect it. It doesn’t matter how deep it is,” she says.

Bishop says mudslides are always a huge challenge, and the massive scale of this one poses significant problems for the dogs.

“It is because the mud can become so compact that the scent just can’t rise out of that tomb, I guess I would call it.”

Another challenge is the loose footing. Bishop says the teams work with others to help navigate the mud, debris and pools of water.

“It’s pretty treacherous, whether we’re on a pile of rubble in a building that’s collapsed or a mudslide, so if I’m busy trying to catch my balance, I might miss something that my dog does that might show he’s indicating some kind of interest in something.”

The teams are all volunteers, but they’ve put in extensive work to learn how to search.

“It takes generally anywhere from two to three years for them to become a certified dog, whether it’s live or cadaver search.”

The teams train two to three times a week to stay sharp, never knowing when they’ll get called to a disaster. So what motivates them to devote so much of their time and energy?

“We’re just willing to go in and do this work because we’re passionate about it, mostly passionate about helping people and working with our dogs. And when we find something we can do with both of those passions, it comes together to be an amazing experience for us.”