Sinkholes and Walking Ferns

Loreen Niewenhuis is an author, adventurer, and Great Lakes speaker. She has completed a trilogy of 1,000-mile adventures exploring the Great Lakes and has written three books about the Great Lakes [A 1,000-Mile Walk on the Beach *a Heartland Indie Bestseller*, A 1,000-Mile Great Lakes Walk *winner of the Great Lakes Great Reads Award*, and A 1,000-Mile Great Lakes Island Adventure]. To learn more about her work, or to book her as a speaker, go to http://LakeTrek.com

During my speaking tour in the eastern U.P., I had time to do a quick hike near Cedarville.

A couple who attended my talk at the library told me that they had a sinkhole on their property. These form when limestone is slowly dissolved by water and this type of formation is called 
karst topography.

Sink hole in background

Maya the dog gives scale to this depression (note the stream of water disappearing in the middle of the sinkhole)

 Also on this property, there was an unusual plant, a "walking fern" in the genus Asplenium. This name comes from the way the plant propagates: new plants grow where the arching leaves touch the ground making it appear that the plant is "walking."

walking fern

This property was wonderful to explore.

Tree atop a limestone ledge

Misery Bay

I hiked the trails in 

Ontario's Misery Bay Provincial Park 

on Manitoulin Island.

This park has some of the best examples of alvar habitat, these large, exposed areas of limestone.

Some still bear the scrape marks from the glaciers.

The horizontal lines are glacial scrapes

This is a rare "puddingstone" among all the limestone

The limestone along the shore has been shaped by Lake Huron

Many fossilized corals are exposed in the limestone

Here's a large chain coral

Limestone flats = Alvar 

Inscription Rock on Kelleys Island

The islands of Lake Erie hold some unique history. On Kelly's Island, there is a large slab of limestone where Native Americans used to carve messages.

It is thought that these pictographs gave information about hunting and fishing sites on and around the islands and told of events in the area.

Inscription Rock under protective roof

While the rock has been weathered over time, there was a sketch made of the pictographs by an army Captain that preserves some of what has been eroded away.

This is a representation of a drawing made by Captain Seth Eastman (of the US Army) in 1850 

The rock is over 32 feet x 21 feet

The weathered carvings are still evident on the rock

Loughbreeze Bay B&B

I stayed at several B&Bs while hiking the north side of Lake Ontario in Ontario, Canada. The B&B owners were all wonderful and helped me to understand their communities and the history of the Canadian side of this Great Lake.

Did you know that the earliest settlers to parts of Ontario along Lake Ontario were colonists who were loyal to the British Empire who fled north after the Revolutionary War?  

About a third of early settlers were not supportive of the war, and the most adamant of these people were called "Loyalists." 

After the war, they left this new country and began fresh in Canada which was still under British rule. 

The Loughbreeze B&B is nestled along the shore of Lake Ontario near the town of Colborne, Ontario

Frances Linton-Schell (on the right) and her husband, Lawrence, were gracious hosts

Loughbreeze B&B

Back yard of the B&B overlooking Lake Ontario and Presque Isle Park

The Holcim Corporation owns a limestone mine near the B&B

Frances called over to the nearby mine in order to get permission for us to walk through it. 

NOTE:  Don't enter mines without the proper permission and guide. They can be unsafe -- often blasting the walls of the mine away with dynamite -- and it is illegal to trespass onto their property.

Limestone mining operation

Frances gives me a tour of the large mine

The mine offloads limestone directly onto ships at their dock

Warsaw Caves Conservation Area

I hiked this geologically significant area located between Lakes Huron and Ontario. It was here (just NE of Peterborough, Ontario) that a wall of water over 50 feet tall rushed as the flow of the upper Great Lakes stopped flowing north and rushed to the south. This happened approximately 10,000 years ago. This reversal was due to a combination of the land to the north rebounding from the weight of the glaciers and the melting of ice dams which had prevented flow to the south. 

When the water changed course, it marked this area in a unique and dramatic way.

Natural Resources Under the Surface of Michigan

Michigan has a wealth of natural resources that have been exploited over the last 175 years.  

A unique person in Michigan's history is Douglass Houghton.  He was an explorer, geologist, doctor, statesmen, and one of the first professors at the University of Michigan. 


Houghton was charged with exploring Michigan in the early 1800s to locate natural resources that could be used to develop and settle the state.

The old docking station for the gypsum mine

Houghton discovered a gypsum deposit south of Tawas City in 1837 and it has been mined for over a 100 years.  Gypsum was first used as a fertilizer and wall plaster, but is now mainly used to make drywall.

Current pipeline for to take gypsum to lake freighters

Cement plant and mine in Alpena

There are two sprawling cement plants that I have hiked around, one in Alpena and one in Charlevoix.  The one in Alpena (in photo above) has been operational for over 100 years and currently produces 2.5 million tons of cement each year.   

Calcite Mine in Rogers City

The largest open pit limestone mine is located in Rogers City.  I was able to get a tour of the Calcite Mine and was amazed by the scale of the operation there.  This mine celebrates its 100-year anniversary this year.  

Calcite Mine in Rogers City

Limestone has many uses from the production of steel and pharmaceuticals, it can be mixed with salt to de-ice roads in the winter, it can be boiled up with sugar beets to remove impurities. 

Trucks at the mine transport over 200 tons in each load 

Yes, that's me in the loader at Calcite Mine

Rogers City & The Purple Martin Inn

The Purple Martin Inn

Marilou and Ruth showed me around the inn and town

When I got to Rogers City, I stayed at a unique place.  This building (to the left) used to be a commercial laundry facility that would do laundry for lake freighters working the Great Lakes.  The business closed long ago and the building is now undergoing a radical transformation into an inn/community gathering place/non-prof to support work with foster kids.


Cindy Vezinau is the  visionary behind the Purple Martin Inn.  She is working to make it as "green" as possible, using recycled, reclaimed, and repurposed materials at every juncture of the renovation.  


The inn is named after the Purple Martin colony that returns to summer at the property every year.  It was a joy to sit on the balcony overlooking Lake Huron and watch the birds in flight.  The Purple Martin population has been dwindling in recent years, so it was encouraging to see this thriving community of birds in Rogers City.

Purple Martin in flight

The Purple Martin Inn is also a place for the community to gather.  This year, the first "Martin Mania" weekend festival which included a dance at the main intersection in Rogers City and a bonfire on the beach near the inn.


When the inn is complete, profits will be used to support work with foster kids.  Rogers City has had a camp for foster kids for many decades, and the partnership with the inn will help to continue this important work.  

Interior of Inn

Reclaimed barn wood finishes this ceiling

The inn is still undergoing its transformation and will open sometime next year.  To learn more about this project, check out their Facebook Page.

Rockport Quarry

I have always been a bit of a rock hound, so when I read about an abandoned quarry (now a state park) on my route, I planned to check it out.




The Rockport Quarry is located NE of Alpena along the Lake Huron shoreline.




On the way there, I came across nice specimens of fossilized coral.




This large pile of rocks are the tailings from the quarry operation. Note the people in the shot to grasp the scale.




The next photo is of the actual quarry. It's difficult to capture how large an operation this was. This quarry is over 300 acres and was the site where limestone was extracted for the supporting structures of the Mackinac Bridge!




I wish I had more time to poke around. Since I am backpacking, the only thing I took from the site were photos.








This baby groundhog (final photo) was more curious than frightened, so I chatted with him for a bit.

Learn more about this park HERE

Location:NE of Alpena, MI