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During 1986-89 nearly 27,000 ha of Shenandoah National Park (SNP) were defoliated by the gypsy moth (Lymantria dispar), inflicting wide-spread habitat alteration, overstory cover loss, and hard mast failure. Gypsy moth primary hosts were the oaks (Quercus spp.), which comprised 55% of the study area. We examined aspects of black bear (Ursus americanus) habitat use during years (1987-89) of extensive defoliation and compared the results to predefoliation years (Garner 1986). In all seasons, relative habitat use differed between the time periods. Females used cove hardwood and black locust more, especially in late summer and early fall, because of cherry abundance. Bears did not avoid defoliated habitat in summer during peak defoliation, nor did they increase use of gypsy moth nonhost stands (e.g., yellow poplar [Liriodendron tulipifera]). In fall, bears avoided defoliation and preferred chestnut oak (Quercus prinus) only in October, corresponding with fall excursions made by 21 of 50 females. Although oak habitats were preferred in fall prior to defoliation for acorn consumption, most bears in this study did not move away from defoliation to areas of abundant hard mast.