Parastagonospora nodorum is a necrotrophic fungal pathogen that causes the disease septoria nodorum blotch (SNB). SNB reduces yield by decreasing the photosynthetic area of the plant. Because wheat lines containing the Snn5 gene are sensitive to the P. nodorum-produced necrotrophic effector (NE) SnTox5, the Snn5-SnTox5 interaction plays a significant role in the development of SNB. In previous work, the Snn5 locus was mapped to the long arm of chromosome 4B using a double haploid population derived from the SnTox5-insensitive T. turgidum ssp. carthlicum accession PI 94749 and SnTox5-sensitive durum variety Lebsock (LP749). Here, we used the same population to develop a saturated genetic linkage map of the Snn5 region. We developed 24 new STARP, SSR, and indel markers that detected loci near the Snn5 locus. The map now contains a total of 62 molecular markers with a density of 1.6 cM/marker. Snn5 was delineated to a 2.8 cM interval corresponding to 1.38 Mb in the Chinese Spring reference genome. We are currently in the process of developing a high-resolution genetic linkage map of the Snn5 region using an F2 population derived from PI 94749 and the SnTox5-differential line LP29, which carries the Snn5 allele from Lebsock. Other ongoing work, including the development of additional markers, the identification of candidate genes, and the development of Snn5-disrupted mutants will be presented. This research will extend our knowledge of the wheat-P. nodorum system and aid in the development of SNBresistant wheat via genomic selection and/or gene editing.