What was it that shook residents in rural Waushara County out of their sleep Wednesday morning?

"I've never experienced anything like that in my life. It was strange, scary," Kevin White said.

Residents near the Town of Leon say they felt the ground shake and heard a strange noise. Even the town chairman.

"We were doing chores this morning in the barn about 4:30, and all of a sudden everything shook, rumbled, and the cows jumped a little bit and kind of looked around, and then my brother and I both heard a noise," Chris Sorenson said.

Anna Syke was in the middle of a good night's sleep when something woke her. "I was sound asleep, 4:20 in the morning, and suddenly I wake up and the house is shaking. The best you can describe it as you would experience in an earthquake."

She was expecting the worst while fearing it was all in her head.

"Nothing came on the news. I called a sheriff's department employee that I'm friends with and he had no information, and then a neighbor called me at 5:30 and confirmed exactly what I felt."

The call was from White, who felt and heard the same thing about a mile away.

He woke up because his cabin was shaking like a freight train.

"First I thought, 'Am I having a dream?' but I can't be having a dream. I thought it was an earthquake. I never experienced an earthquake, but that's what I thought an earthquake would be like," White said.

He said it sounded like thunder but was a constant rumble moving from south to north, and he could feel it through the cement slab. A minute-and-a-half later, it happened again.

White called the sheriff's department, which told him it received similar calls from other people and that it was investigating.

Given no explanation, White decided to take a look for himself.

"What it got light at 7 o'clock, I went and hopped on the snowmobile to see if I could find anything out in the woods, and I couldn't find anything out of the ordinary."

"There's a big block of 300 acres to the east of me that something could have crashed in there and you may not find it for quite a while," White offered.

"Did something crash? Did something explode? We have a lot of cabins out by us that are unoccupied, so that was going through our mind," said Syke.

The sheriff's department tells Action 2 News its deputies searched the area for a cause, like a plane crash, but came up with nothing.

The National Geological Survey and utility providers had nothing to report, either.

Which leaves those who felt and heard the rumblings to wonder what woke them.

"I've never had this happen to me in my life, and it's kind of scary when your whole foundation is shaking. You kind of want to know what's, what's going on, you know? It's unexplained," said White.

"Any answers we can get, because we're all just completely baffled, everyone who lives out here, and I think a little bit shook up -- literally, figuratively!" Syke said.