Are There any Volcanoes in South Dakota? Kind Of
The eruption of the Kīlauea Volcano in Hawaii has been a fascinating event to follow. Fascinating to me, thousands of miles away and safely experienced through my TV and computer. I'm sure it's a very different experience for the people living on the Big Island.
The eruption in our fiftieth state got me thinking. Do we have any volcanoes, or possible volcanoes, in South Dakota? East River doesn't really have the obvious signs of volcanic activity. It's flat (flat-ish anyways) farmland. The hills here look like they were mostly made by wind and water erosion; and the retreating glaciers at the end of the last Ice Age.
West River, however, has the Black Hills. That is where we can find the closest thing to a volcano in South Dakota. It's what is known today as Bear Butte. It is also known as Mato Paha or Bear Mountain to the Lakota and Noahvose to the Cheyenne. It's long been a sacred religious site for many Native Americans.
Bear Butte is in a state park in the Black Hills of South Dakota near Sturgis. It rises 1200 feet above the surrounding area. Like a mountain alone in the sea of grassland. It's not actually a butte, meaning an area rising from the surrounding land caused by erosion. A butte is made when the land is worn away leaving a kind of big hill. But, Bear Butte is a geological laccolith.
Some fifty-million years ago, magma (molten rock; it's called lava when it comes out of the ground) pushed up the crust of the Earth in the area. Like your foot pushing up the bed sheets, the magma pushed up until it formed Bear Butte. If the magma would have punched through the bubble it was making (ripped through the bed sheets) Bear Butte would have erupted into a full fledged volcano.
It built the building, left it standing and didn't do much else. Erosion from wind and water then took over and sculpted what we see today. Bear Butte may have actually erupted when it was formed, or sometime in the distant past, but the erosion likely destroyed the evidence.
So Bear Butte is probably the closest thing we have to a volcano in South Dakota. And if we're all lucky we'll never know any different. Running from lava flows and ash don't sound like a lot of fun. Then there's the lava bombs to deal with, oh and the always fun pyroclastic flow.