The Lower Narrows is a large gap and one of three major gorges that cut through the 50 mile circumference of the Baraboo Range. These gorges were created by rivers more than 500 million years ago and then buried by sediments in a vast sea over the next 150 million years. Wind, water and glacial erosion later exposed them again. The Baraboo River now flows through the Upper Narrows gorge near Rock Springs into a basin surrounded by the Baraboo Range, and exits at the Lower Narrows. Known for its ancient rock formations, the gorge has vertically tilted Precambrian pink Baraboo quartzite rock ribs on both walls, while red rhyolite rock more than 1.5 billion years old is visible on its northeast flank along Highway 33. Devil’s Lake, in the longest and deepest gorge of the Baraboo Range, formed when that gap was blocked by glacial debris 15,000 years ago. Geologist and University of Wisconsin president Charles R. Van Hise said that no other region in Wisconsin illustrated so many principles of geology.