Ozark mountain forests in Arkansas, Missouri and Oklahoma are experiencing widespread oak mortality coinciding with increased populations of red oak borer, Enaphalodes rufulus (Haldeman) (Coleoptera: Cerambycidae). Red oak borer, a native long horned wood-boring beetle, has an unusual two-year life cycle with synchronous emergence in odd numbered years. Though it is endemic to areas throughout the northeastern U.S., it has not been indicted as a causal agent of mortality in other oak decline events. Intensive and extensive sampling of 58 northern red oak, Quercus rubra L., from the Ozark National Forest in Arkansas ranging from apparently healthy to recently dead, reveal populations that are deviating extraordinarily from previously published numbers, e.g. 110 mean live larvae per tree (SE ± 19) compared to 2-3 documented historically. Also presented is a survey method developed to enable rapid population assessments, which provides acceptably accurate estimates of population variables at the stand and landscape level. Data generated through this research will permit detailed studies of red oak borer biology and mortality and should help us better understand causes of this outbreak.