Michael W. Garthaus, Kentucky Department of Fish and Wildlife Resources, 30 Scenic Acres Drive, Murray, KY 42071. Roy C. Heidinger, Cooperative Fisheries Research Laboratory and Department of Zoology, Southern Illinois University at Carbondale, Carbondale, IL 62901-6511

Abstract. The objective of the study was to determine if there were spatial differences in proportional stock density, relative weight, and age and growth of largemouth bass (Micropterus salmoides) in Kinkaid Lake, Illinois. Kinkaid Lake is located in Jackson County, Illinois, and was impounded in 1971. The lake has a surface area of 1,113 ha and a maximum depth of 22 m. Spatial heterogeneity was found in the largemouth bass population between two sites within Kinkaid Lake. Overall, bass from the Ava site exhibited better population structure, condition, and growth rates than bass from the marina site. Reservoirs in southern Illinois can have largemouth bass populations exhibiting spatial differences in population structure, condition, and age and growth.