Interstate State Park Glacial Potholes

The potholes are the work of the last ice age. As the great glaciers melted, torrents of meltwater rushed through here with tremendous force, and the swirling water trapped stones in eddies that spun round and round in one spot. Turning like drill bits for years on end, those stones ground deep, smooth-walled shafts straight down into the solid rock.

The rock they cut is basalt, ancient lava laid down more than a billion years ago when this region was tearing apart and floods of molten rock welled up across the land. That hard, dark stone preserved the potholes almost perfectly, leaving one of the best displays of these formations anywhere on Earth.

Below the potholes, the St. Croix River squeezes through a narrow gorge called the Dalles, where sheer walls of basalt rise steeply from the water. The name comes from a French word for such rock-walled river passages, and the dramatic cliffs make this one of the most scenic stretches of the St. Croix.

The river here is a protected wild and scenic waterway, forming the border between Minnesota and Wisconsin. Seasonal boat tours glide through the gorge beneath the towering rock, giving visitors a view of the cliffs and potholes from the water below.

The St. Croix valley is part of the homeland of the Dakota and the Ojibwe, or Anishinaabe, who traveled and lived along this river long before the towns rose on its banks. The river was a route and a resource, and the Ojibwe and Dakota both knew its waters and the rich country around them.

In the 1800s the St. Croix became a highway for the logging boom, floating vast quantities of white pine downriver to the mills. Taylors Falls grew as a river town in that era, and its historic homes and buildings still climb the bluff above the water beside the park.

Beyond the potholes, the park offers trails that wind among the rock formations and along the river, and the basalt cliffs draw rock climbers to their vertical faces. The compact terrain means a lot to see in a short walk, from pothole to overlook to riverbank.

Spring and summer bring green to the gorge and the boat tours to the water, while fall sets the wooded valley ablaze with color reflected in the river, one of the finest times to visit. Winter quiets the park and frames the dark cliffs and river against the snow.

The closest Boutel™ stays, so you can turn this stop into an overnight. Each is an independently owned, editorially selected place to stay.