Crayfish is a globally diverse group of invertebrates and one of the most important taxa in North American streams. Many crayfishes are identified as species of concern due to anthropogenic alteration, narrow distributions, and interactions with invasive crayfish. An estimated 48% of North American crayfish are at risk of extinction and widespread stream changes may result from loss of crayfish species despite their important role in stream structure and function, including a primary diet item of Smallmouth Bass (Micropterus dolomieu). The project is a collaboration between the Oklahoma Department of Wildlife Conservation and the Oklahoma Cooperative Research Unit. We will compile existing crayfish data, determine the hierarchical structure of habitats associated with crayfishes, determine crayfish demographics, and determine factors related to the spread of non-native crayfishes within the Ozark Highlands ecoregion. These data are valuable for developing strategies for removal in possible locations, monitoring vectors if necessary, and developing important linkages between key prey and sportfish populations.