Whitebark pine blister rust (Cronartium ribicola) is an introduced pathogen affecting whitebark pine (Pinus albicaulis) and limber pine (Pinus flexilis). Whitebark pine is an endangered species protected under the Federal Species at Risk Act (SARA) and Limber pine is designated as an endangered species by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC). Infection and mortality rates of these species are increasing across their northern range. Every five years, data are collected from permanently marked plots to monitor infection levels across the mountain national parks. Survey data are collected to quantify infection in Yoho National Park to inform management action