About this spot
Castor River Shut-Ins sits inside the Amidon Memorial Conservation Area east of Fredericktown, reached via County Roads J, W, and 208 to a small gravel lot; note that many GPS apps mislocate the site several miles south, so following the posted route matters more than a dropped pin. Pink granite shut-ins channel the Castor River into a short run of chutes and a modest pool around six feet deep, with a low rock ledge used for informal jumping. It is smaller and calmer than the better-known Johnson's Shut-Ins nearby, making it popular with families, per the state conservation department and regional swimming-hole guides. There is no lifeguard, and the smooth granite is slick when wet; water levels and flow depend on recent rainfall, so scout conditions before jumping.