Whitebark pine seeds are arguably the most important fattening food available to grizzly bears during late summer and fall. We annually monitor cone production throughout the GYE on 19 transects. Cone production is highly variable from year to year. Our studies have demonstrated a relationship between cone counts and bear mortality. In years of poor cone production, bear conflicts and deaths increase. Understanding such relationships is useful in predicting and preventing future problems. Ironically, whitebark pine is potentially threatened in the GYE by an introduced fungus, white pine blister rust, which could significantly reduce pine abundance. Blister rust has already decimated whitebark pine in northwest Montana. Infection occurs in the GYE, but as yet has not caused extensive tree mortality.