The subpopulation is an intermediate level of organization that is ecologically meaningful for research and management. We used location data (n =  1,235) from 54 barren-ground grizzly bears (Ursus arctos) monitored from 1974–78 (n =  12) using VHF (very high frequency) telemetry and from 2001–06 (n =  42) using GPS (global positioning system) telemetry to delineate subpopulation structure in the Mackenzie Delta region of the Northwest Territories, Canada. We used Ward's cluster analysis to group bears into 4 subpopulations using their geographical position in 4 seasons. We used the fixed-kernel method to bound subpopulation areas and to estimate the relative probability of use by each subpopulation for each geographic information system (GIS) grid cell. The Delta is the starting point for the proposed Mackenzie Valley Pipeline. To demonstrate how subpopulation structure can be used to partition potential anthropogenic disturbance across the population, we estimated the mean probability of use of the projected pipeline route for each subpopulation from the initial development to 2027. Mean estimates of the probability of use suggested that the future pipeline development would occur disproportionately among subpopulations. Improved understanding of subpopulation structure facilitates research, monitoring, and management initiatives in response to changing land use.