The Castor River Shut-Ins display Missouri's only known pinkish-colored granite rocks in a shut-in

Photo byFacebook/Amidon Memorial Conservation Area.

A shut-in is an interesting geological feature found in streams in the Ozarks region. A shut-in is a curious rock formation that carves through mountain ranges, creating a confined area within a narrow valley or canyon.

There are over 90 shut-ins in and around the St. Francois Mountains region of southeast Missouri. The Castor River Shut-Ins is one of them.

A shut-in is a geological feature similar to a gorge that “shuts-in” the river. Water cascades through billon-year-old rocks, creating chutes, pools and waterfalls. (Source.)

The Castor River Shut-Ins are Missouri's only known pinkish-granite shut-ins, and are located in the Amidon Memorial Conservation Area at County Road 208 in Fredericktown, Missouri. Amidon Conservation Area was named for Evelyn and Ellsworth Amidon. They donated part of the area to the Missouri Department of Conservation in 1984.

Photo byFacebook/Amidon Memorial Conservation Area.

Shut-ins occur where a stream is shut in to a narrow canyon-like valley. They typically occur where streams flow through softer sedimentary bedrock materials such as dolomite or sandstone and then the streams approach the more resistant igneous rock.

Castor River flows through the area with pools, the shut-in, and small waterfalls. Downstream of the shut-ins you might see colorful small fishes, go fishing, or go wading. Also downstream is where Hahn's gristmill operated during the 1870s by two brothers, Fred and John Hahn.

Photo byFacebook/Amidon Memorial Conservation Area.

One of the most famous shut-ins in MIssouri is Johnson’s Shut-Ins, but the Castor River Shut-Ins is considered a hidden secret worth exploring in the summer.

The Amidon Memorial Conservation Area has been open to the public since 1993. There, you can hike, fish, hunt, and swim in the Castor River. The pink granite shut-ins are supposed to be a sight to see. Since the current can become stronger after it rains, it's suggested you wear a life jacket in what's defined as a natural waterpark.

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