SIOUX FALLS, S.D. (KELO) – Good Samaritan Society residents took a plunge hundreds of feet below the interstate Friday. They got a tour of the Knife River quarry.

Residents were in for a bumpy ride as they made their way into the quarry in Sioux Falls.

They ended up at this staging area in the south hole, which is about 280 feet below the interstate.

“Quite an adventure, I’ve never been in a hole this big before and to learn the history of the area and city,” Good Samaritan Society resident, Joyce Tlustos said.

“In this particular tour, we brought the bus down to a safe staging area where you could look over the operations as they happened, we are an active mine and operating, and we want to make sure everybody is safe,” president of Knife River South Dakota, Clark Meyer said.

Drive down a little bit further and now you’re 320 feet deep.

President of Knife River South Dakota, Clark Meyer says they’ve been giving tours of the quarry for over 20 years.

“People drive by on the interstate or Madison and wonder what’s at the bottom of the hole and we think it’s important that they get to see what’s at the bottom of the hole but also educating them on why it’s important to the community, what the reserves and resources are used for and how they impact the community and end up being part of the community,” Meyer said.

He says this part of the mine began work in the 1980s.

Residents may realize the memories this trip digs up.

“Some of the residents probably saw the mining beginning at the surface level and to see it now developed and at the depth it is, is very entertaining for them,” Meyer said.

“You don’t realize the immensity of it like I said, a unique experience,” Tlustos said.

Quartzite is the main product being mined in the quarry. It’s used for ready-mix concrete, asphalt concrete, pipe bedding and other base material for construction.