Mountain pine beetle developed to epidemic levels in lodgepole pine stands in the Thompson River drainage in 1971. Approximately 506,616 trees are infested on 4,444 hectares. Based on buildup ratios, infestations are expected to intensify; develop in uninfected stands; and kill about 1,763,024 trees in 1977. Salvage logging of infested trees and silvicultural management to reduce the average stand diameter below 20 cm d.b.h. are recommended to manage the infestation.