Operational resilience in western US frequent-fire forests

•With changing climate, resilience has become a management objective but is difficult to quantify.•Minimal competition supports vigorous tree growth which may have been associated with resilience.•Using the stand density index, we show historical forests were largely free of competition.•In contrast, most contemporary forests are in full competition or imminent mortality.•Resilience in frequent-fire forests may require significantly reducing tree densities.