The cumulative forest area impacted by the recent mountain pine beetle epidemic in western Canada has exceeded 17.5 million hectares and drawn significant attention.22 When a host tree is killed by mountain pine beetle, the tree’s crown will fade to red (known as red attack stage), and eventually, the dead tree will shed its needles (known as grey attack stage). This characteristic change in the color of the tree crown makes mountain pine beetle damage well-suited to detection with a variety of remote sensing instruments. High spatial resolution satellite imagery has been used to provide stand-level information for mountain pine applications, including mortality mapping8,14,23–25 and assessing changes in the location and extent of infestations over time.26 High spatial resolution digital aerial imagery has also been used for a range of information needs: observing damage over large areas or to individual trees,27,28 mapping the spread of infestations and estimating the severity of attack,28,29 and determining environmental conditions that enable attack.29 Digital aerial imagery can be used to verify ground-based estimates of mortality and extend those estimates across larger areas.27,28 Given the capacity to resolve individual tree crowns with high resolution digital aerial imagery (Fig. 1), tree attributes such as crown size, foliage area, and inference of diameter at breast height can be derived, over a range of accuracies, for all the trees on an image, rather than for small sample plots.29 Tree species can be identified or inferred, enabling estimates of the population-at-risk to infestation. In addition, stand conditions can be examined to determine what, if any, forest management practices have been applied to the stand. Digital aerial imagery can be used in sampling schemes to determine attributes such as the number of infested trees in an area28 or the rate of population growth.30 Furthermore, this imagery can serve as an important source of calibration and validation data for map products generated from lower spatial resolution data sources8,27,31 or as inputs to insect-spread models.29 Finally, digital high spatial resolution imagery provides a permanent record of stand conditions that can subsequently be interrogated for retrospective analyses26,27 or for other applications.