The Arkansas River Shiner (ARS), Notropis girardi, is a federally threatened minnow that now occurs natively in modest numbers only in the South Canadian River, following decades of range contraction and population losses. The remaining populations are at increasing risk as global change is expected to impact the upper and middle South Canadian River with a rise in temperature as much as 4-6 F and a decrease in precipitation from 10 to 35 % in this century. The primary objective of this project was to evaluate potential effects of habitat and environmental change on Arkansas River shiners by examination of habitat use and availability at several spatial scales using both historical and recently-collected data from seven sites within the South Canadian River within the boundaries of the Great Plains Landscape Conservation Cooperative. We examined variation in habitat/environmental factors over time and/or space and the relationship of that variation to river discharge and asked if variation in abundance of Arkansas River shiners in collections was explained by habitat/environmental variation.