Mountain pine beetle has occurred at epidemic level in lodgepole pine stands in the west Gallatin River drainage since 1969. Infestation now encompasses about 5,500 acres. Since 1969, approximately 463,212 trees, with an estimated volume of 20,529,244 board feet have been killed. Approximately 69 percent of the stands on the Gallatin District are classed as susceptible. It is predicted that about 927,781 trees will be killed in 1976. Selective logging to remove infested and susceptible trees is recommended to reduce the potential for a continued epidemic.