Abstract We studied the life history and ecology of the Greenbrier Crayfish, Cambarus smilax (Loughman, Simon & Welsh, 2011) in Thorny Creek and the West Fork of the Greenbrier River, West Virginia from August 2010 to July 2011. We gathered data on morphology, reproductive status, habitat preference, and the prevalence of claw regeneration for each monthly sampling event. We collected Form I males every single month at Thorny Creek location, and every single month besides December at West Fork Greenbrier location. Females exhibited active glair glands during May to July, with oviposition in June to August. Fecundity ranged from 71 to 179, with an average of 121 eggs per female. Cambarus smilax preferred different microhabitats at each of our two study sites. It was primarily collected in run microhabitats at Thorny Creed, but primarily collected at West Fork Greenbrier within pool microhabitats, potentially due to competitive displacement from C. chasmodactylus (James, 1966). Our study provides the first information regarding the life history of C. smilax and sheds light on the ecological implications of competition between locations with different crayfish communities.