A photographer’s paradise with its natural rock bluffs. This gorge is referred to as a shut-ins. Shut-ins occur where a broader stream is “shut in” to a narrow canyon-like valley. In Missouri, shut-ins typically are found where streams flow through softer sedimentary bedrock such as dolomite and then encounter more resistant rock like rhyolite. Rhyolite is considered an igneous rock, one formed from magma, molten rock.
Above the creek valley the vegetation is stunted growing on the open rhyolite rocks with a western exposure. These igneous glades provide harsh growing conditions. Short-statured and gnarled blackjack oaks are scattered across the rock outcrops.
Along the creek valley the rare winterberry and northern arrow-wood occur. Both of these species are only found in the Ozarks in Missouri and only at scattered locations along rocky streams such as this. They provide fruits valuable to songbirds.
In the creek lives the Big Creek crayfish. The world-wide distribution of this crayfish species is restricted to the St. Francis River basin of Iron, Madison and Wayne Counties. This crayfish prefers small, high-gradient rocky creeks. Unfortunately the introduction of crayfish species not native to the St. Francis River basin can cause problems for the Big Creek crayfish. Inter-basin transfers of crayfish species through bait bucket dumping and other methods have caused declines in many endemic crayfish populations.
(7 miles south on Hwy 21)
