Special Report: Mystery Valley

There’s a piece of land in Presque Island County that’s left people scratching their heads for decades.

For this special report Corey Adkins spent some time with the Michigan Karst Conservancy to try to unlock the mystery of Mystery Valley.

“This is Mystery Valley, which has been a curiosity in Michigan for many years,” said Gary Richards with the Michigan Karst Conservancy.

It is a place where science, geology, time and gravity all came together to create this lake that’s baffled people for decades. Ty Black is a geologist who’s been studying Mystery Valley.

“This is a Karst Valley caused by the collapse from below in a very deep cavern system about 900 feet below us. The gypsum has been removed by groundwater and so the roof couldn’t support that that wide of birth and then where there were natural fractures. It’s where major collapse has occurred,” explained Ty.

Let’s dumb it down a bit. Think of it this way: Imagine your house being built on gypsum and limestone and years of water dissolving all that away. When that’s all gone, gravity kicks in and your house sinks.

But here’s the mystery: the lake is either here…or it’s not.

“For the last four years Mystery Valley Lake has formed and we don’t know why. Whether the opening to the swallow hole has collapsed or a cavern has collapsed blocking the water flowing out. It could be because the levels of Lake Huron are high and the water cannot flow towards Lake Huron,” said Bill Houston with the Michigan Karst Conservancy.

Just four years ago this lake was dry.

“Four years ago we actually mowed the valley. We cut the grass so that our visitors could walk all the way out to the swallow hole and actually see the swallow hole,” said Bill.

Bill has been taking his kayak over the lake over the past four years and you’d be shocked at the water levels.

“Around June 19th of this year I did my first series of measurements of Mystery Valley, which is now filled with water. It was 25.5 feet when I did that measurement. The swallow hole was almost 30 ft. deep, but as you can see, my paddles are about 8 and I have to raise it to actually touch the top and that would be the height of the water. This is totally impressive,” said Bill.

The trees around the lake give the proof. Almost a 13 foot difference in water level since June, but why is the lake here this year and not others. They think the lake is connected to Lake Huron through underground caverns.

“There is a relative relationship with the levels of Lake Huron and such. But it’s precipitation levels. The more precipitation you have in the area, the more groundwater or in the more water reaches the ground and starts to flood the karst system. And just like a sewer or a septic system, they can only take so much flow. The karst system can only take so much, so if we have lots of precipitation feeding into it, it would be like a river overflowing its banks. So that’s why we see water in Mystery Valley right now where normally this time of year it would be dry,” explained Ty.

And that’s not the only mystery around the preserve. There’s sinkholes and earth cracks to explore.

It’s an ever changing piece of land, always different and because of that they ask you stay out of the earth cracks. They’re home to frogs, salamanders and rare flora.

“I am astounded by the Earth cracks. The changes in the vegetation, it’s on the sides of the earth cracks, the marshes the ferns and the liverworts and also what’s fascinating is the number of new swallow holes,” explained Bill.

Mystery Valley is a place that doesn’t care about technology. It’s a place where science, geology, time and gravity came together all at one time and will leave us with one of Northern Michigan’s best kept secrets.

“It’s absolutely amazing. It’s a mystery,” said Bill.