Today we explored the Interstate State Park in Wisconsin along the St. Croix River. This place has geologic significance. One billion years ago lava was laid down from a volcano 100 miles from here. When the ice melted it moved in a river and the rapids were so quick that rocks, sand and pebbles could go in a crevice and carve the lava forming a pothole which are like pots. They could be 15’ deep and 6 or 7’ wide.
During the Ice Age a glacier covered a lot of the area forming many of the interesting formations that we see today. One of types of the formations are eskers which are formed when a retreating glacier has a steam that drops pebbles and sand under the melting ice. The hills look like a serpent. Drumlins are elongated hills that are like eskers but not curved. End moraines are glacial dumps at the end of a glacier. Kames are cone-like hills that are formed by streams flowing with sediments moving down a hole in the ice called a moulin. A kettle is formed when an ice block melts below the ground making the surface fall in, forming a pond.
After these geologic process people came to the area. Some of the native Americans who lived near here were the Ojibwe who gathered wild rice from the marshes. The “wild rice” is not actually rice, but rather is a seed of a grass.
French fur traders and trappers were some of the first Western people to come to the area looking for beaver pelts and other furs. They named many of the local rivers and places. After them came the loggers looking for the white and red pines. They cut down the trees and floated them down the St. Croix river, creating mile long log jams!
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