County: Madison County, Missouri
Nearest City: Fredericktown
Trailhead: 37.568918, -90.154981
Distance from downtown STL: 1 hour 45 minutes / 100 miles
Trail Length: 1 mile
Trail Format: Loop
Land Management: Amidon Memorial Conservation Area
Camping: Primitive dispersed camping
Shut-ins Location: 37.5689, -90.1495
Watershed: Castor River
Castor River Shut-ins is an impressive formation with a unique pink-ish color. While other shut-ins may cast red hues, the vibrant pink rhyolite here is absolutely striking. Before recognizing the native glade plant life, one might mistake photos of this area as being from another state.
Opening widely in the forest and nearly a quarter mile long, everything about this shut-in feels grand. Giant boulders the size of Volkswagens are strewn about its course. Rising up in sheer pink granite, the walls of its northern bank form a stunning backdrop to the numerous riffles and cascades.
As you reach the end of the shut-in the stream flows into a large pool before turning south for a final run. Picking up speed in a solid chute, it roars over one last falls in a grand finale. The valley widens below this point and the stream turns to gravel with dark rhyolite highlights.
Access to the area is a short manicured trail over easy terrain. Unfortunately, short and easy enough to roll coolers down. So you may want to explore elsewhere in the summer unless you are interested in swimming. Cedar Glade Trail loops back to the parking lot after climbing to a high lookout above the Castor River.
Castor River Shut-in is part of the 1,630 acre Amidon Memorial Conservation Area. From Fredericktown take highway 72 east, and then turn left onto State Highway J. Turn right onto highway W and follow signs for Amidon Memorial.
The entrance sign for the conservation area features an old mill stone from Hans Mill. Take a left at this sign to reach the trailhead for Cedar Glade Trail. If conditions permit, you can veer right and ford the river to find an additional parking lot on the right side of the road. Another trail leaves north from this parking area to a swimming hole downstream of the shut-ins (cross the road).
Nearby attractions include Fredericktown City Lake, Millstream Gardens’ Tiemann Shut-in, Lower Rock Creek Shut-in and Rock Pile Mountain Shut-in.