The Pennsylvania Regeneration Study was initiated in 1989 because of concerns about a long history of stress on oak/hickory (Quercus/Carya) forests from herbivory and other factors. The study, which addresses the need for landscape-level information about regeneration quality and abundance, comprises a suite of regeneration indicator measurements installed on a subset of Forest Inventory and Analysis monitoring plots. The State's oak/hickory forests have been under increasing stress because aging stands that originate from large-scale disturbances from more than 100 years ago are inundated by herbivory of preferred plants and invasion of native and nonnative invasive plants. Maintaining oaks in young stands is difficult because of herbivory, invasive plants, climate change, lack of fire, and other factors. This paper summarizes the Pennsylvania Regeneration Study results, offering a look at likely challenges faced by managers and policy makers, as well as by inventory specialists who design forest inventories for stressed forests.