My wife and I recently visited Interstate State Park, which is located partly in Minnesota (next to Taylors Falls) and partly in Wisconsin (adjacent to St. Croix Falls). Minnesota established the park in 1895. In 1900, Wisconsin did the same. The park is approximately 30 miles west of Stillwater, MN, and about an hour from the Twin Cities. According to Wikipedia, the reason for setting aside the land to form a park was to protect the St. Croix River Dalles. A dalles is a rapids formed by water rushing between a gorge or a canyon. At Taylors Falls, the St. Croix River enters an area of cliffs creating an area of rapids.
While the park has the natural beauty we expect along the St. Croix River, my wife and I were particularly interested in examining the potholes of the park. These are not the kind of potholes we usually think of when we hear the term. These potholes are not depressions in roads, but a geographical feature resulting from glacial runoff far back in the history of the area.
There is some disagreement about how the potholes were actually formed. The popular theory, according to sentex.net, is that glacial waters carrying grains of sand and other debris were trapped in depressions in the surrounding bedrock, formed giant whirlpools, and carved holes that are properly known as glacial potholes, but are commonly just called potholes. Interstate State Park contains more potholes in a smaller area than any other location in the world. With a depth of over 60 feet, Bottomless Pit is the world’s largest explored glacial pothole.
According to an article on a University of Wisconsin–Green Bay online website, other theories are offered to explain the formation of the potholes. The article questions whether glacial runoff would have been trapped instead of seeking the easiest way through an area. An alternative theory is that ice dams formed in the area, the dams were breached with a resulting quick runoff of water, and that runoff created the pot holes. A third theory is that water containing sediments was trapped beneath the glaciers, and, under great pressure, formed the potholes.
Whatever the cause, there are more than 80 pot holes in Interstate Park, some with colorful names like Devil’s Parlor and the already mentioned Bottomless Pit.
If geology is not your interest, you may enjoy simply hiking through the park, enjoying the sight of the St. Croix River as it flows through the park, separating the Minnesota side of the park from the Wisconsin side. Climbers will enjoy the challenge of several bouldering and climbing areas in the park. If your nature is one of sitting back and letting someone else do the driving, you may want to book a ride on the Taylors Falls Queen or the Taylors Falls Princess. The excursion service operates just outside the park. Both the Queen and Princess are paddlewheel boats that get you close to the beautiful scenery of the St. Croix River.
During the fall, the park is also a riot of colors as the trees prepare for the winter season. If you’re in the area, take time to explore Interstate Park.
Sources:
en.wikipedia.org/wiki/Interstate_Park
www.sentex.net/~tcc/pothart.html
www.uwsp.edu/geo/projects/geoweb/participants/dutch/geolwisc/geostops/InterstateParkMN.HTM
