Welcome to Tenino, a town whose history can be seen and heard by simply strolling down the main street, where buildings are clad in gray carved stone, and stone cutters tap away with mallets on chisels at The Shed, turning chunks of rock into works of art.

"It gives a lot of character to our town," Keith Phillips said.

Keith is a stone cutter and is talking about Tenino sandstone. Sandstone is a type of rock mined here for generations, and once used for buildings all over the state.

"Tenino is so workable," Phillips said. "It's not a terribly hard stone like granite or basalt. And because it's so workable it can be fashioned into a myriad of different shapes and sizes."

Even the city's swimming pool is made of sandstone -- it's a quarry that flooded more than a century ago.

"That place explodes in the summer -- it is the local swimming hole and cherished by a lot of people," said stone cutter Ed Salerno.

And today, after more than a century, what's at the bottom of this pool will be revealed.

It's an effort spearheaded by the town's mayor, Wayne Fornier

"I do feel a little bit like Indiana Jones today," he laughed. "We'll be diving in the quarry pool, the Tenino Quarry Swimming Pool. We want to find out what's down there. It's been a mystery; there's been a lot of myth and lore surrounding it."

What these waters hide is the stuff of local legend:

"I know as a kid living here, it was something you'd talk about with your friends," Fornier said. They would ask, "what's down there, how deep is it, what happened, are there monsters."

Keith Philips has family ties to the quarry, and has an educated guess as a result. He thinks there are pieces of equipment down there; perhaps cable that was once attached to equipment meant to move the stone around. It’s a guess backed up by historic photos:

"A lot of that wire cable went into the hole just to get rid of it,' Phillips explained, pointing to one of the photographs of the working quarry in his shop.

On dive day, at the quarry, the opinions are more colorful – a couple of boys speculate that there may be bodies down there because some of the quarrymen may not have made it out alive. Teenagers who grew up swimming this pool have heard there’s a crane.

Whatever’s down there, a large group of curious people have shown up to see what Mayor Fornier comes up with.

For the first time ever, sonar is being used to scan the pool.

"They identified something over there that looks like the front of a front-end loader," Fornier said. "That'll be a spot that we definitely want to check out."

Tenino's mayor donned his scuba gear, took a historic leap, and descended into his town's past. Divers used a safety line to guide themselves as they explored the quarry's murky depths.

On the second dive, they did find something.

"We got down there around 65 feet, and something's down there," Fornier said. "It's hard to see, because I can only see about 6 inches in front of my face. But I got my hands on something metal, some kind of metal equipment, [a] metal pipe. There was something large, covered in muck."

That something might be something called a steam channeler – a small locomotive engine used to move heavy equipment.

And they also found the cables Keith predicted would be down there. The team found enough that they are now planning multiple dives on the quarry, and perhaps some recovery efforts.

But the most important thing the mayor of Tenino brought to the surface of the quarry pool is curiosity about his town's history that will go on for another generation.

Tenino Mayor Wayne Fournier was named 2017's BEST Mayor in Western Washington in our annual viewer's poll.

Evening is your guide to Seattle and the Pacific Northwest. Watch it weeknights at 7:30 on KING 5 TV or streaming live on KING5.com. Connect with Evening via Facebook, Twitter, Instagram or email: eveningtips@king5.com.