I was up early on Day 2.
I took this photo from our motel room at the Badlands Inn. Not a bad view, huh? (Minus the telephone wires and fences, of course.)
The Badlands have received an unnaturally high amount of rain this year. Many of the formations are surrounded by green grass instead of brown.
Temperatures will top out at 106 degrees today. So, I don't expect the lush greenness to last much longer.
What do the rocks look like up close? Mostly they look like chunks of mud. And that's pretty much what they are made of.
We started our day with a ranger-led Geology Walk down the "Door Trail". More on that name later...
The ranger informed us that the Badlands tell the geologic history of the area.
79 million years ago, a shallow sea covered most of present-day United States. For 6 million years, black mud settled to the bottom. This formed into a hard rock called "Pierre Shale". Fossils found at this level are cretaceous sea creatures.
Then the Black Hills (70 miles to the west) began to uplift. The bottom of the sea became a boggy shore. The exposed black rock weathered into yellow soil called "Yellow Mounds".
By 37 million B.C., a river flood plain had formed. Each year, for three million years, the river flooded, depositing a new layer of gray dirt. The fossils at this layer suggest an ecosystem dominated by alligators. Prehistoric mammals emerged.
The climate of the next period (30 million to 34 million years ago) was much drier and cooler. Alligators disappeared, replaced by savanna-loving herd mammals. The soils turned brown, and as a result, so are the rocks at this layer. It's called "Brule".
Next up is "Rockyford Ash". Approximately 30 million B.C., volcanoes pumped massive quantities of ash into the air. They produced a dark gray line that delineates the Brule layer from the Sharps layer.
The Sharps layer is the newest deposit of sediment. The climate during the period (28 million to 30 million B.C.) continued to dry out and cool off. Volcanoes continued to spew their ash, which mixed with deposits from wind and water erosion. This layer is gray.
So, to recap from bottom to top: Pierre Shale (black), Yellow Mounds (yellow), Chadron (gray), Brule (brown), Rockyford Ash (dark gray), and Sharps (gray). Only the Brule and above are visible in this area of the park.
Why so jagged? The land was pretty much level between the Sharps period (28 million years ago) and 500,000 years ago. That's when water began cutting into the rock that formed the flat floodplain. The Sharps layer is mostly soft mudstone. It wears away easily. But in the places where small, hard rocks are (or were) present, you get a peak (called a "sharp"). See this picture? The rock at the top (called a "cap stone") keeps the layers underneath intact.
Eventually, enough of the lower structure will erode to the point where the sharp will have no more support, and it will come tumbling down. This peak will then round-off to become a mound.
Trails are marked with poles sticking out of the rock. But you don't have to keep to the trails. In fact, the trails are just rough suggestions. The Badlands National Park has an open hiking policy. I was shocked to hear that they encourage you to climb on the buttes. They want you to walk off-the-beaten-path. There's no permit needed to camp in the backcountry. In fact, with the exception of off-roading in your vehicle, letting your pet run wild, or stealing pieces of the park, pretty much anything goes. So, bring your horse, a bedroll, and a lot of water, and head out into the wilderness!
Don't worry. I'm wearing a thick coat of sunscreen. Oh, wait, you're looking at where I'm standing. Yeah, it's interesting out here on the edge.
Finally. The reason the trail is called "Door" is because it ends near this small rock formation. It is called a "door" because the opening provides access to walk through to the other side.
This is the destination for the "Window Trail". Why window? This opening allows you to see the other side, but you wouldn't dare walk through it.
