Johnson's Shut-Ins
At Johnson's Shut-Ins, the East Fork Black River encounters Precambrian-age volcanic rocks. The valley walls converge dramatically and the stream plunges over a series of enclosed rapids called shut-ins. Igneous rocks exposed along the river tell a fascinating story of violent volcanic eruptions that occurred more than a billion years ago in the St. Francois Mountains Section of the Ozark Natural Division. Johnson's Shut-Ins Natural Area also includes gravel bars along the river, dry igneous forest, igneous glades and extremely rugged igneous talus slope communities. A separate state park brochure interprets the geologic and natural history of this area.
Johnson's Shut-Ins Natural Area
Access Information:
GPS park office.
Map:
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