Castor River Shut-Ins

In the foothills of the St. Francois Mountains, one of the oldest mountains in the Americas at almost 1.5 billion years old, lies the curious place known as the Castor River Shut-Ins. Also known as Pink Rocks, due to the igneous rhyolite granite that they are formed in, these natural water slides are part of one of nature’s best amusement parks.

A shut-in is a place where water has carved smooth “slides” through soft rock, in this case Missouri Pink granite, and forms a canyon through which the waters flow. Missouri is home to several of these geological features, including the Johnson’s Shut-Ins in Lesterville, but none are so beautiful and mostly undisturbed as the Castor River site.

These shut-ins are found on a section of the Castor River that is a little more than half a mile long and flows through the Amidon Memorial Conservation Area. The area is accessed by a short, well-maintained, mostly flat path that takes you to the start of the granite area. From there, you can start climbing on the rocks or veer off to the right and climb the hill to walk above the river. Either way, the views are absolutely stunning. The path does eventually turn off away from the river and makes a loop back to a spot on the entry trail close to the parking lot, but most people just use it to access the boulder-strewn canyon that has been there for eons (Well, one and a half eons if you are being technical).

So, what will you see? First, a walk through a typical Midwest Missouri hardwood forest. Then you will hear the river and waterfalls just before the trail turns and the beauty of the area first slaps you in the face. And it is a hard slap, like when your girlfriend catches you watching another girl’s wiggle. Alas, this is only the beginning of the awesomeness that nature has to offer here, and your cheeks are about to get numb from all of that slapping you’re about to get! Once at the water’s edge, you see that there is a beautiful, clear river coursing through sublime pink granite. If you are there when it has just rained, the pink hue of the rocks turns to a deep hue. One might wonder how the rock got to be pink. Well, as with other famous areas nearby, like Elephant Rocks State Park, it is the result of ancient volcanic activities. Yep, Missouri used to have lava bubbling up to the surface!

After you have spent a few minutes taking in the sights, turn around and start looping around the boulders that are downstream from here. This is where you will really start to understand what makes this the most magical place in Missouri, and one of the top natural wonders in America. The series of waterfalls, pools, slides, boulders, and cliffs, interspersed with short-leafed pines, scrub oak, mosses, ferns, and a myriad of other plants and features, all covered with aqua-colored lichen and wildflowers that cling to impossible crevices, will instantly soothe your soul. Speaking of soles, you will want to wear sturdy sneakers or water shoes, as you will be climbing on, over, under, and through boulders of all sizes. They range from the size of a football to that of a small warehouse. And they are all VERY smooth. As in slippery. And once in the water, you will really be glad if you brought an extra pair of old rubber-soled shoes or water shoes to keep from getting gravel embedded in your skin.

During the summer months, swimming down the river is a favorite pastime. The water is always cool, as it comes from a spring upstream, and is so very awesome when the needle on the thermometer is bending around the peg at the far end of its travel. If you bring a set of goggles or a mask, you can swim underwater and see the awe-inspiring collection of pebbles and rocks on the bottom, or say hello to the fish that make the river their home. Lots of interesting types of fish at that, from sculpin to smallmouth bass. Some crazy fools actually take their camera in the water and get down as low as they can go to get really cool shots without dunking the Nikon into the drink. Surely no one has ever actually done that, but make sure to keep your camera strap out of the water too.

This is one of the prettiest places in the Midwest, and it doesn’t matter what time of year you go. In fact, it may be that it is prettiest after a good snow. But it contains beautiful scenery in winter, some of the best fall colors for hundreds of miles in any direction, and this is a great spring wildflower spot.