Badlands National Park

While it is interesting to see the wildlife of Badlands National Park, the real star here is the geology. The soils that can be seen in the exposed cliffs were laid down for tens of millions of years or more. Both the colors and shapes of the badlands are evidence of the geological history of this part of South Dakota.

At the bottom of the deep ravines, a dark grey material is the oldest of the visible strata. This rock, says signs in the park, is known as Pierre Shale (described by the U.S. Geological Survey as "dark-gray clay shale with calcareous and ferruginous concretions and sandy members") and is the result of sedimentary mud that once lay at the bottom of a sea that covered what is now Badlands National Park. Because of its origin, this layer contains fossils of sea life such as ammonites, early clams, and baculites.

The Pierre Shale was deposited over the Upper Cretaceous period, also known as the Late Cretaceous period which lasted from about 98 million years ago to about 65 million years ago. At the end of that time, the vast sea that covered this part of North America receded mainly due to the rising elevation of the area caused by tectonic activity (the shifting of the Earth's plates). The sea floor mud formed fertile ground and not long after the waters retreated, geologically speaking, it was covered by a thick jungle.

Yellow Mounds Paleosol and Interior Paleosol

Decaying plant material mixed with the top layers of the Pierre Shale over the next 28 million years or so, resulting in a layer of yellowish soil. This layer is called the Yellow Mounds Paleosol. At some point around 37 million years ago, the jungle was covered by new sediments carried from the west. The minerals contained in this layer of soil were different than those of the Pierre Shale, so when the jungle grew up again in this new layer, the action of the plants and the organic material they mixed with it resulted in a soil with a strong reddish tint. This layer is called the Interior Paleosol.

The Colors of the Yellow Mounds Paleosol and the
reddish purple Interior Paleosol are visible on the steep sides
of deep ravines in Badlands National Park.
Photo by Brad Sylvester. Copyright 2011, all rights reserved.

Both the Yellow Mounds and Interior Paleosols were later covered again, becoming packed and fossilized by the weight of later sediments. Their distinctive coloration, however, can be seen in the cliff-sides exposed by erosion over the millenia.

Popcorn Rock or Bentonite Clay

More hints about the geologic history of Badlands National Park can be found in the make-up of much of the top layers of soil within the park. Although the area gets little rainfall for most of the year, the soil through much of the roughest areas of the park looks like dried mud. Indeed, it is, but mud of a very interesting nature.

It is a clay called Bentonite by geologists, but known as ball clay or popcorn rock in the local vernacular because of its unique properties. When it does rain in this arid part of South Dakota, The South Dakota Badlands Bentonite, because it contains sodium instead of calcium as it does in some other regions, says John P. Bluemle, absorbs the water and expands to many times its original size. The repeated expansion and contraction as it dries again causes it to break up so instead of a smooth surface, you end up with rough balls of hard packed clay that are an inch or two in diameter.

Bentonite or Popcorn Rock covers many of the steep hillsides
in Badlands National Park.
Photo by Brad Sylvester. Copyright 2011. Do not copy.

These clay balls will often break away from the hillside and roll down the into the ravine when they get wet. When this happens, their soft outer surface will often pick up pebbles as it rolls. If you look carefully at the bottoms of the gullies, you might find some of these clay balls that look like someone took hours to stud them with a variety of small rocks.

Bentonite is formed from the breakdown of volcanic rock and ash. With the super-sized volcanic caldera of Yellowstone National Park lying not too far to the northwest of Badlands National Park, it's pretty easy to determine the origin of the badlands bentonite.

Clastic Dikes

Clastic dikes run down the center of many of the clay hills
of Badlands National Park.
Photo by Brad Sylvester. Copyright 2011. Do not copy.

Another interesting geologic feature helps to give the badlands its rugged appearance. Clastic dikes are vertical wall-like structures of harder rock that erodes more slowly than the surrounding bentonite and paleosols. The result is that it often looks like the spine of the mountains, sticking up with vertical sides from the surrounding rock and soil. Clastic dikes are interesting formations that also tell us something about the history of this land.

According to Harman D. Maher Jr. of the University of Nebraska at Omaha's Department of Geology and Geography, it is believed that clastic dikes are formed when tectonic activity causes the ground to move in such as way as to open up deep crevices. These open crevices are quickly filled in either from above or possibly from liquefied material being forced up from below. This filling material solidifies almost like cement leaving a vertical wall of harder rock encased in softer surrounding soils.

Because of the way it is formed, the material of the clastic dikes may be of a different geological age than much of the material surrounding it. Furthermore, sometimes these crevices open and fill more than once. So if a clastic dike already existed and the same crevice opens again, but wider, the original clastic dike may be encased in a another layer of material, showing several vertical layers of different types of rock when the clastic dike is eventually exposed by erosion.

Source note: Much of the geologic history of the Badlands is told by signage within the park itself or was related to me by park rangers, and it is these that serve as the primary resource for the geological history that I relate here. Where other sources are used, they are referenced within the text.

Road Trip Day 4: Badlands National Park

View from an overlook along the Sage Creek Rim Road in
Badlands National Park, South Dakota

The fourth day of our road trip across the country was really the first day where we didn't need to worry about putting lots of miles behind us. This was a planned day of "rest" sightseeing at Badlands National Park in South Dakota. Badlands is a big place and I'm going to break it up into several parts. One of the things we hoped to do when we came out west was to see wildlife that simply isn't present back east.

One of the smaller of these is the prairie dog. Although small, prairie dogs serve a vital role in the prairie eco-system as a food source for a variety of mid-sized predators, like foxes, badgers, raptors, bobcats, and the endangered black-footed ferret. They also help churn and aerate the soil with their prolific burrowing. But, this is a blog about sightseeing and not about wildlife management, so I'll skip the details about prairie dogs (which, in Badlands National Park, by the way, are of the black-tailed variety,  specifically of the species Cynomys ludovicianus).

• See my prairie dog pictures here 

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Prairie dogs are visible in several spots around the Badlands Loop Road, but the best place to view them is near the Pinnacles Entrance along the Sage Creek Rim Road. Shortly after entering the park, there will be a right hand turn-off marked Sage Creek Rim Road. It's a dirt road, but it is well-groomed and easily passable by any car during the dry season at least. There are several scenic overlooks in the first few miles along this road, and you should definitely take the time to stop and look out over the landscape here. At the five mile mark, however, is Roberts Prairie Dog Town.

Here, on flat level ground, far enough away from any ledges to let the kids walk around without worrying, there is a parking area and a little walkway into the prairie dog town. The town consists of many, many prairie dog burrows. You'll see prairie dogs sitting as sentinels near one of the two entrances to each burrow around the field and others grazing on the grasses seemingly without a care in the world.

At this location within Badlands National Park, the prairie dogs seem accustomed to people and didn't startle as easily as those in other locations I visited. Even so, never feed wild animals even when they seem tame. Prairie dogs don't drink water at all, so they need to get the right mixture of water and food through the grasses they eat. Adding dry crackers or other artificial foods to their diets can throw off their balance, especially if they contain salt. Additionally, once they start to expect food from humans they seek out people and may spend more time in and around the road near the parking area exposing them to additional risk.

A Prairie Dog crouching in the entrance to its burrow at
Roberts Prairie Dog Town in Badlands National Park, SD

Feel free to wander into the prairie dog town, watch them go about their activities, and take all the pictures you want, just watch out for the holes in the ground and the occasional wandering bison. While we were there, one lone bull bison was grazing a couple hundred yards away from the parking area. We kept a wary eye on his position lest it approached closer than the 100 yard minimum distance recommended by the park rangers. It never did.

Money-saving Tip

If anyone in your group is 62 years of age or older, they can buy a lifetime senior pass for just $10. This pass let's them and anyone else in the car into any National Park for FREE-- just another reason to travel with the in-laws.  At some national monuments and other sites, it offers a discount on admission as well. (Mount Rushmore is the exception - no discount for senior passes there.) Otherwise, Badlands National Park admission is $15 per car load, but that admission is good for seven days.

Road Trip Day 3 - Wall, South Dakota

My wife and I by Dam #7 on the Mississippi River
Photo by Barbara Gammon, Copyright 2011. Do not copy.

We drove through hundreds of miles of corn fields on day three of our cross country road trip. We crossed the Mississippi River which was bigger than I expected it to be this far north. We stopped and took a few pictures at the crossing in Minnesota near Lock and Dam #7. I hadn't realized that the Mississippi had locks installed to make it navigable as far north as St. Paul. It makes sense though, as the information sign at the rest stop points out that the from source to mouth, the Mississippi has a vertical drop of 1488 feet, of that, 857 feet of drop occurs between the Mississippi's source at Lake Itasca and the northern border of Iowa.

After the Mississippi, I-90 climbs up onto the plains. More corn fields. Interestingly, though, the corn fields here are doing double duty as wind farms. Rows of modern windmills stretch as far as the eye can see. I couldn't tell which manufacturer produced these windmills, but the website Wind Energy, The Facts says that the most popular models produce 1500-3000 kW of power.The U.S. Energy Information website says that the average U.S. home consumes just under 11,000 kW hours per year. For comparison, the average coal-fired power plant in the U.S. produces roughly 220,000 kW of power though this type of plants vary widely in size and output.

Windmills ended abruptly once we reached South Dakota, despite the fact that there were just as many corn fields along the highway. They seemed to be replaced with billboards which lined the highway. As a native Vermonter, where billboards are prohibited by law, I ordinarily prefer landscapes uncluttered by advertising. In South Dakota, however, they only serve to break up the endless corn fields.

I'm beginning to suspect, however, that the quality of the attraction is inversely proportional to the number of billboards on the route to it. Wall, South Dakota and, specifically, Wall Drug have the highest billboard count along I-90. We did not expect much from Wall and our expectations were met. We arrived in the early evening and checked into the first place we saw, the Sunshine Inn. We asked for a non-smoking room and got one that smelled of smoke. Continental breakfast consisted of prepackaged cinnamon rolls, coffee and orange juice. It was cheap in every possible meaning of the word.

Wall Drug itself is essentially a small mall full of tourist shops. Several gift stores, a cowboy boot shop, leather goods, camping equipment, knives, books, jewelry, and similar offerings are peddled from individual stores inside the Wall Drug complex. There is  T-Rex robot that comes to life every 12 minutes or so and a small outdoor area with some static displays. For me the most interesting thing was the photo wall in the very back building. While it mostly chronicles frontier life, there is one photo that more accurately reveals "how the west was won." It shows a number of U.S. Cavalry Soldiers posing proudly on horseback in and around a mass pit grave filled with native American bodies at Wounded Knee. Read Lorie Liggett's introduction to Wounded Knee here.

Don't feel compelled to make a stop at Wall Drug, its reputation and billboards notwithstanding, there's not much to see here. The best thing about Wall, South Dakota, is that it is located at the entrance to the Badlands National Park. We ate dinner across the street from Wall Drug at the Cactus Cafe & Lounge. Not recommended. They offered an all-you-can-eat dinner buffet for $10.95 which featured a soup and salad bar, spaghetti, fried chicken, baked beans, and pizza. It was not particularly good, but it was close and easy after a long day of driving.

Me posing with the Green Giant.
Photo by Linda Sylvester, copyright 2011.
Do not copy.

I should also mention that we had a celebrity encounter in Blue Earth, Minnesota. We actually had the opportunity to get our pictures taken with the famous Green Giant. There's a sign next to him which gives some statistics such as the fact that it cost $43,000 to build him out of fiberglass and that he stands 55 feet six inches tall. You'll have to go to Blue Earth and read the sign for yourself to see which of the Green Giant's body parts measures 48 inches...