Landbird populations across the US and Canada, and in constituent regions like the Pacific Northwest (PNW), have declined markedly over recent decades. In 2005, we began monitoring population trends of bird species across five PNW national parks, including three large, mountain parks and two small, lowland parks. By 2016, we found that population densities of most species commonly detected in these parks had been stable or increasing since 2005. We attributed this stability to warming springs and diminishing snowpack; many of the species achieved higher densities after low-snowpack winters and warm springs. However, a shift in elevation might also allow some species to track favorable climatic conditions. To test this hypothesis, our current analysis used data from 2005 through 2023 to assess more recent population trajectories and to determine whether populations in the mountain parks had shifted up- or down-slope during this period. We found mainly weak evidence for elevational shifts in many populations, and no bias in the direction of shifts (up- or down-slope). These results, combined with the observation that bird populations in lowland parks were also robust during the monitoring period, suggest that elevational shifts alone do not explain the resilience of birds in these parks.