Many social movement researchers question the usefulness of political opportunity as a concept. However, others argue that it can be refined by disaggregating different opportunities for actors and outcomes to understand the underlying mechanisms that influence each. This research extends this analysis by asking "political opportunity for whom?" Looking at Canadian Aboriginal mobilization, it assesses how different opportunities influence a broad range of movement actors and organizations. Using data from a 50-year period it assesses how contemporaneous, lagged and change regression modeling of opportunities affect results. The article finds that structural opportunities around resources robustly influence a wide range of mobilization. (Contains 3 tables, 1 figure, 7 notes.)