Tennessee tailwaters are routinely stocked with brown trout Salmo trutta and rainbow trout Oncorhynchus mykiss to sustain put-and-take and put, grow, and take fisheries. Natural reproduction is known to occur in some Tennessee tailwaters. Natural reproduction can enhance the quality of a fishery and reduce the reliance on hatcheries to maintain a fishery. However, current stocking regimes ignore natural reproduction as a source of population enhancement because the subject is not well researched. The factors which control trout reproduction in Tennessee tailwaters are poorly understood. The objective of this study is to identify the factors necessary for natural reproduction to occur. This study is focusing on four east Tennessee tailwaters; little or no natural reproduction is thought to occur in two rivers (Clinch and Hiwassee), but substantial reproduction has been documented in two other rivers (South Fork of the Holston and Watauga). Complete censuses of spawning activity commenced in October 1998 and will continue through two spawning seasons. In addition to assessing habitat quality, other factors such as fecundity and brood stock size will be investigated.