
When I was a kid, our parents would occasionally take my brother and me to what we called the “Castor River swimming hole” or alternatively, the “Castor River Shut-Ins.” Mom, as usual, fretted about our safety, while we boys just enjoyed the sweep of water through the tight passages of rock, bouncing downstream to where Dad waited to catch us.
There are a couple of swimming holes on the upper Castor, a river that receives much less attention than its more famous cousins to the west, and I honestly can’t remember which one we visited in my childhood. But one of the most unexpectedly beautiful places in the Ozarks is what is now the Amidon Memorial Conservation Area in northeast Madison County.
If you’ve visited Elephant Rocks, you know the remarkable pink granite that crops up in places across Iron, St. Francois, and Madison counties. At Amidon, that pink is lighter than at other places, far more sculpted, and shaped by the flow of water into a remarkable display.

Why doesn’t the Castor get more attention? It’s shorter, for one thing, and it quickly traverses from dramatic shut-ins to a relatively uninteresting, muddy stream, with lots of debris and agricultural runoff. But for several stretches, it’s as beautiful as anywhere in the Ozarks. Its lack of fame means that you’ll probably have the place almost to yourself, although do note that most of the ownership along the Castor is private. So you have to look for access points. The pink granite is unearthly in its strange beauty, and the flooding and debris has created a rich alluvium that lends to the growth of wildflowers in abundance.
I don’t think I’d let my kids bounce down through the shut-ins, though, unless the water was pretty low.
