My first question upon learning about this state park was, “What’s a shut-in?” I had images of people with frail health in group homes.

In a nutshell—this river is “shut-in” by hard, ancient volcanic rock (rhyolite) that does not erode away like sedimentary rock. This section of the Black River cannot “wander” out of its banks to create new channels like other rivers do. These rocks in question are slick with algae, making navigating between them a challenge even with good shoes to help, but we had a lot of fun climbing over and between the shut-ins as the rocks are then called.

There are two safety systems in place for the dangerous flash floods that do occur here, especially when the water is channeled through a confined area like a shut-in. The flag system lets you know when the water is at “safe” levels to enjoy getting in, and there is a warning siren that means climb 200 steps up to safety now.

The flags were changed to green on the day we left. Park personnel were not around when we arrived, so we think they were updating for the holiday weekend and the coming summer crowds. It wasn’t really yellow for our two days of water fun.

This rock is part of a debris field near the entrance to the Shut-Ins area. If flood waters can move boulders like this, one can see how a siren system would save lives in a flash-flood event.

Like a waterfall, the noise level was loud and I had to be close to Tony to speak with him.