Our last stop on the way to Michigan was the Indiana Dunes National Lakeshore which is on the southern edge of Lake Michigan. There is also the Indiana Sand Dunes State Park in the middle of the national park. It is not a contiguous park as there are several parts that are separated from the main section. This park encompasses a variety of habitats to see and learn about. The eco systems represented here are: lakes, beach, dunes, interdunal, marsh, swamp, savanna, prairie, rivers, bogs and fens.
The park has 15 miles of beach along the shores of Lake Michigan. The lake, of course, was formed from glaciers along with the other 4 Great Lakes. The glacier here was continental (not the montane ones I’ve been writing about in Washington). The ice sheet was up to 2.5 miles thick. There were about 4 different glacial periods, the latest being the Wisconsin about 20,000 years ago. The glaciers still moved and flowed like the montane glaciers, and ground the rock down into sand. Lots and lots of sand. When the glaciers retreated, creating the lakes, sand also began being deposited as dunes. The water levels fluctuate causing the shorelines to move accordingly. There are places where older dunes, deposited when the lake was larger, can still be seen. These older dunes support trees.
As the dunes move with the shoreline and water levels, they end up looking like contour lines on a map (if you look at satellite images). The areas between the different ridges of dunes are interdunal wetlands.
Marshes and swamps are here to view as well. The difference between them is the tree cover. Marshes are mostly grasses and herbaceous plants while swamps have mostly trees. The Great Marsh is being restored and has both habitats represented. We hiked through this part of the park. It was interesting in the variety of plants visible. And we saw evidence of beavers (gnawed upon logs). Speaking of being gnawed upon…during our hike through the marshlands the mosquitos were extremely hungry. Even with bug spray, clouds of mosquitos swarmed and hummed around us constantly. Yes, a few even partook of a nice meal at our expense.
There are small sections of both prairie (tallgrass) and savannas. The difference between these two habitats is the tree cover (Am I repeating myself here?). Savannas have between 10-80% tree cover. Prairies have 10% or less of trees. There are two prairies here, one being the Calumet Prairie State Nature Preserve and is run in conjunction with the state park agency. The other is the Mnoke Prairie and is near the Bailly Homestead area.
Bogs and fens, both a type of wetlands, are interesting. A fen gets its water from below ground, while a bog is created from glacier ice. The bog here is called Pinhook Bog. It can only be viewed during an escorted ranger hike. This is due to the fact that the bog is extremely rare so it is being kept in as pristine condition as possible. The really interesting thing about it is that everything floats on a very dense mat of sphagnum peat moss. Trees, bushes, everything. The moss is so thick it can even support people walking on it. Unfortunately we could not see this part of the park at the time we visited.
There is even a historic link to the history of flight for the area. Octave Chanute was one of the pioneers in exploring flight in the early 1900s. He corresponded and talked to the Wright Brothers in Dayton, Ohio while they were developing their first airplane. He experimented with his glider here amongst the dunes.
All in all, it was a very pleasant visit. There are lots of hiking trails (70 miles of trails between the state and national parks), it is dog friendly (Kip and Kellie got to go to the beach with us!), and there are a wide variety of flora and fauna to enjoy. Just remember to bring the gallon or two of bug repellant (per person) which will be needed to keep the mosquitos and ticks at bay.