The mussel is triangular in shape with the dorsal margin nearly straight and the ventral edge rounded in the shape of a bow. The shell is thick and can grow up to 4.5 inches in size. Growth ridges and grooves have distinct color changes. It is a heavily sculptured mussel.

 In Kansas, an obligate riverine mussel adapted to mud, silt and silty gravel substrates where it prefers quiet water areas and usually buries itself in the soft mud of the river bottom. Historically occurred in medium to large streams in the Marais des Cygnes basin.

Rock Pocketbook Mussels are protected by the Kansas Nongame and Endangered Species Conservation Act and administrative regulations applicable thereto. Any time an eligible project is proposed that will impact the species’ preferred habitats within its probable range, the project sponsor must contact the Ecological Services Section, Kansas Department of Wildlife, Parks and Tourism, 512 SE 25th Ave., Pratt, Kansas 67124-8174. Department personnel can then advise the project sponsor on permit requirements.

As defined by Kansas Administrative Regulations, critical habitats include those areas documented as currently supporting self-sustaining population(s) of any threatened or endangered species of wildlife as well as those areas determined by the Kansas Department of Wildlife, Parks and Tourism to be essential for the conservation of any threatened or endangered species of wildlife.

 Currently, the following areas are designated critical for Rock Pocketbook Mussels:

• The Marais des Cygnes River from the confluence of Hundred and Ten mile Creek (Osage-Franklin Co. border) to the Kansas-Missouri border (Miami and Linn Co.).
• Pottawatomie Creek from the confluence of the South Fork of Pottawatomie Creek (Anderson Co.) to the confluence with the Marais des Cygnes River (Miami Co.).
• Marmaton River from the outflow of Fort Scott's waste water treatment facility to the Kansas-Missouri border (Bourbon Co.).