New sources of resistance are needed to effectively manage the Ug99 lineage of the stem rust pathogen, Puccinia graminis f. sp. tritici. In a search for such resistance, landraces from the USDA - National Small Grain Collection were screened as adult plants in the field at the International Rust Nursery in Njoro, Kenya and as seedling against race TTKSK in the greenhouse at the Cereal Disease Laboratory. Single plant selections of PI626573, a spring wheat hexaploid landrace identified as resistant to TTKSK at both adult and seedling stages, were used to develop recombinant inbred populations to study the inheritance of the resistance. Segregation analysis of 164 F3 families at the seedling stage suggested that the resistance in PI626573 is conferred by a single dominant gene. Homozygous resistant and susceptible individuals were identified in the F2 generation through F3 phenotyping and used in bulk segregant analysis (BSA) to identify microsatellites (SSR) associated with the resistance. The BSA identified nine SSR markers associated with resistant or susceptible phenotypes. All nine markers are located on the long arm of chromosome 2B. Additional SSRs located on chromosome 2B were mapped to identify markers flanking the resistance gene and provide a skeletal map of the region. A high resolution map is under development and will be used for map based cloning.