Thinning of mature lodgepole pine stands (Pinus contorta var. latifolia Engelm.) changed forest structure in ways that increased the diversity and abundance of secondary bark beetles (Coleoptera: Scolytidae). In particular, increased coarse woody debris and wind speeds in thinned stands relative to unthinned stands were associated with increased diversity and abundance. Thinned stands also enhanced dispersal in pine engraver bark beetles, Ips pini Say, measured as increased number of days above the temperature threshold for flight (19°C) and reduced dispersal costs in terms of fat consumption. Further, pine engravers in thinned stands had more mates, longer egg galleries, more eggs, and higher egg densities relative to unthinned stands. These multiple influences on bark beetles suggest that increased population sizes due to thinning may be reduced by minimizing the amount of coarse woody debris remaining after thinning, monitoring coarse woody debris input after thinning, and maintaining higher tree densities.