Cronartium ribicola (Pucciniomycotina; Pucciniomycetes; Pucciniales; Cronartiaceae) causes the white pine blister rust. This invasive pathogen has devastated white pines of North America, once a dominant group of tree species. This heteroecious rust fungus requires alternation on two different hosts, Ribes spp (currants, gooseberries, etc) and white pines (Pinus strobus, P. monticola, P. lambertiana). The disease is also threatening high elevation ecosystems, by causing mortality and preventing regeneration of keystone species such as P. flexilis and P. albicaulis, which are now an endangered species. Tree resistance has been discovered and is deployed in some pine species. There is a need to further our understanding of how this invasive pathogen can attack and kill pines and to develop tools to monitor the pathogen and prevent the development of new races. The genome sequencing of C. ribicola is part of a larger effort, the Pathobiome Database For Bioenergy Trees Project, that aims to sequence the genomes of multiple pathogens that share the same host trees in order to identify common and unique genomic signatures. These data will be used to create a database that will help the development of tools for the detection, monitoring and surveillance of pathogens in these economically and ecologically important trees.