Sinkhole Country

Northeastern Michigan is sinkhole country. It has nothing to do with our economy at present. Geological structures. Shakeholes. Swallowholes. Sinkholes.

A sinkhole is a depression in the earth’s surface caused, here in Michigan, by the chemical dissolution of carbonate rocks–like limestone and dolomite. Groundwater is what mostly causes the rocks to dissolve.There is a gradual removal of these somewhat soluble bedrock deposits and, often suddenly, bedrock is not quite so bedrock anymore. Geologists call northeastern Michigan, especially around Onaway, Lachine and throughout Presque Isle County, a karst landscape. It explains why we mine so much limestone around these parts.  Northeastern Michigan’s karst landscape is shaped by dissolving layers of soluble limestone. The Michigan Karst Conservancy is working hard to preserve some of Michigan’s sinkholes, including “twin” sinkholes in Alpena County. Unfortunately, and sadly, they are under attack by forces that include illegal trash dumping.

You are looking into sinkhole #1 (of 5) at Sinkholes Pathway, near Shoepac Lake. Shoepac Lake is also a sinkhole, but it’s filled with water. You’ll find it at N 45° 14.606, W 084° 10.121. If that doesn’t work for you, it’s about 10 miles South of Onaway. Take M-33 south to Tomahawk Lake Highway. Turn east, following the signs to Shoepac Lake Campground. There are some “sinkhole” signs too.  Small, brown, and easy to miss. (The signs, not the sinkholes.) Parking for the Sinkholes Pathway is about a mile beyond the campground, on the west side of the road by Shoepac Lake. The sinkholes are on the east side of the road.

This is not a heavily attended site. The trails need grooming. And don’t lean very heavily on the handrails. When you see the condition they are in you won’t be tempted to lean at all. But it’s a very cool place:  a 2.4 mile loop of 5 sinkholes.  At sinkhole #1 you can walk those 219 steps down, and take the 438 steps back up.

Here’s the map at the trailhead:

Here’s the FREEP’s report on the area:

Here’s another view of Sinkhole #1:

And here’s the demon in the wizard hat who guards the sinkholes. It saw the formation of three of them. Take heed of the wild-eyed gaze and the tongue frozen mid-scream in a curled back position. Pray you are not present when sinkhole #6 forms.