Interstate State Park
Wisconsin’s oldest state park preserves basalt cliffs, giant potholes, and St. Croix River views opposite Minnesota’s companion park.
Artwork inspired by Frances Myers
Glacial meltwater once drove sand and stones in powerful eddies that drilled the park’s giant potholes into ancient basalt. The narrow Dalles of the St. Croix now separates two state parks, making the river simultaneously a geological corridor, jurisdictional boundary, and federally protected scenic waterway.
The Wisconsin and Minnesota parks require separate vehicle permits and are not connected by an in-park pedestrian bridge. On the Wisconsin side, begin with the pothole trail, then choose a river overlook or longer forest loop. Rock edges are polished, irregular, and exposed; winter ice and high water demand more caution than the short mileage implies.
- Founded
- 1900
- River
- St. Croix
- Rock
- Ancient basalt
Quick guide
- Inspect the spiral walls
- Look for rounded abrasion and trapped stones that reveal meltwater force
- Planning catch
- Two separate state parks
Use one pothole to understand an entire gorge
- Inspect the spiral walls
- Look for rounded abrasion and trapped stones that reveal meltwater force.
- Face across the boundary
- The opposite cliffs are another state park with separate roads, permits, and facilities.
- Separate cliff from trail
- Short routes can contain exposed edges, stone steps, and slippery bedrock.
- Add river history
- Logging, dams, tourism, and protection all changed how people used the gorge.
Good to know
A Wisconsin sticker does not cover the Minnesota park, and reaching the opposite rim requires driving outside the parks.
Notice these
- Pothole Trail
- Dalles gorge
- St. Croix overlooks