is the result of molten magma injected by underground explosions up into vertical cracks of the rhyolite over several hundred million years. Each geologic layer forms distinct units, with colors varying from violet to red to maroon to gray and thicknesses from 25 to over 900 meters.
As geologic time passed and the volcanic activity ceased, weathering and erosion removed the existing topography and carved the area into a hills and valley landscape. Topographic relief was still greater than today-with differences of more than 2,000 feet from mountain top to valley floor. Today that distance is less than 1,000 feet.
During the next geologic era, the Paleozoic, ancient rivers and seas deposited limestones and dolomites, sandstones and shales initially in the valleys and later, higher up the side slopes, burying the Precambrian volcanic landform. Remainders of these sedimentary rock layers still are exposed on the lower slopes of the hills and in the valleys. This region, along with the rest of the Ozarks, experienced more uplifts during the end of the Paleozoic Era. The upper elevations of the old Precambrian surface were resurrected, as soils and sedimentary layers were eroded away.
The erosion continues today, but within the natural area boundaries, we are able to view the remaining ancient topographical surface much like it appeared millions of years ago.
If these antique rocks could talk, they could clear up the various tales about the region. The legends naming the Taum Sauk Mountain and the Devil's tollgate and explaining the formation of Missouri's highest waterfall, Mina Sauk Falls, all involve an Indian tribe called the Piankashaw.
European settlers forced the tribe out of the east, and they passed through Missouri on their way to the Indian territory of Oklahoma.
Though there are no facts to support the legend, it is said that Taum Sauk, the chief of the tribe, had a daughter, Mina, who was in love with a warrior from the hostile Osage tribe. The falls were formed when Mina threw herself off the mountain to her death after her people had killed her Osage lover in a similar manner. The Great Spirit sent a bolt of lightning which split the mountain top, and a stream of water flowed over the ledges, washing away the blood of the lovers. You can still see blood-red flowers, known as Indian Pinks, that grow along the banks of the stream each spring.
The rocks can tell us something about the