Leaf rust, caused by Puccinia triticina Eriks (Pt)., is a wide-spread disease of wheat that is capable of inciting significant yield losses. Leaf rust can be controlled by deploying effective leaf rust resistance (Lr) genes in cultivars. However, the Pt population is dynamic and evolves over time. For example, in 2011 there were 70different Pt races that were identified in Canada alone. To keep pace with pathogen evolution different strategies are employed to develop resistant cultivars including identifying new Lr genes and developing DNA markers to allow accurate selection of Lr genes. Combining Lr genes can help prolong the effectiveness of resistance but is difficult to achieve by phenotype due to epistasis. Recently, a new Lr gene,Lr70, was identified in the wheat accession KU3198. A second resistance gene, Lr52,was also present in KU3198 making it difficult to assess the effectiveness of Lr70 as Lr52 is a broadly effective gene. Initial genetic mapping with SSR marker placed Lr70 on chromosome arm 5DShowever the markers did not show close linkage and SSR markers are less desirable for marker-assisted breeding compared to SNP markers. The purpose of this study was to identify improved DNA markers for Lr70 and to assess the effectiveness of Lr70 against a diverse set of North American Pt isolates. Using multiple sources of SNP markers, we were able to identify SNP markers based on the KASP assay that were more suitable for marker-assisted breeding. Our assessment of Lr70 with a diverse set of Pt races showed that Lr70 conferred resistance against all races tested and is broadly effective. Given these results, Lr70 is a valuable resistance gene for North American wheat breeding programs and the new markers will allow responsible deployment in combination with other Lr genes.