Meramec Mosaic

Points of Interest:

• Explore a wide range of natural communities supporting over 400 native plant species.
• See lush bottomland and slope forests and open dry glades and woodlands all in one hike.
• Enjoy the Meramec River – a globally important site for freshwater mussels.

Natural History:

This area includes a diverse assemblage of natural communities representative of the Meramec River Hills of the Ozark Highlands including woodlands, dolomite glades, fens, dolomite cliffs, upland and bottomland forests, caves, springs, Beaver Creek, and the Meramec River.

Traversing the natural area westward from the lush bottomland forests along the Meramec River and lower Beaver Creek with towering sycamore growing over a thick understory of pawpaw and spicebush an adventurous visitor can head upslope through white oak dominated dry-mesic forests on north-facing slopes with flowering dogwood and many spring wildflowers. Nearing the ridge top on west and south facing slopes, widely spaced, stunted, gnarled chinquapin oaks grow on thin rocky soils. Here the ground is resplendent with native grasses, goldenrods, and asters. Dolomite glades support dazzling wildflower displays. These restored glades and woodlands represent thousands of hours of labor by park staff and volunteers in clearing invasive eastern red cedars and subsequent prescribed fires. Birding is also good here for a variety of resident and migratory breeding birds.

Underground is a network of caves and underground conduits that support populations of the rare Onondaga Cave amphipod, a diminutive crustacean that inhabits cave streams, drip pools and groundwater passages. Other animals inhabiting the caves include a number of bats: the eastern pipistrelle, northern long-eared bat, little brown bat, the Indiana bat, and the gray bat (these last two bats are listed as endangered and threatened, respectively, by the U.S. Fish and Wildlife Service). Bats are important consumers of insects, including mosquitoes.

The Meramec River’s mussel fauna is one of the most diverse and unique in North America (the world’s center of freshwater mussel diversity). In particular the lower Meramec River is a hot spot for globally rare mussel species. Besides having funny names, freshwater mussels have a fascinating life cycle, with mussels relying on specific host fish species for their larvae to develop into young mussels. One of the more common mussels in the Meramec River, the three-ridge, can use several species of fishes for its larval development. Other species such as the pink heel-splitter can only use one fish species, in this case freshwater drum. Unfortunately freshwater mussels are disappearing from Missouri and North America at an alarming rate due to water quality and stream habitat degradation.

The Meramec River was going to be impounded in the 1970s by the U.S. Army Corps of Engineers with the dam located at Meramec State Park. In 1978 citizen groups opposed to the Meramec dam successfully passed a referendum in opposition to the dam with 64% of the vote. Today this stretch of the Meramec is recognized as an Outstanding State Resource Water.