The resilience of social, biophysical, and technological systems is of increasing scholarly and practical import. Guided by scholarship on disaster resilience, environmental inequality, and urban service inequality, we advance the study of "unequal resilience" in a critical infrastructure - the electric grid. We analyze inequality in electricity outage duration at the census block group level using data from the U.S. Census, the U.S. Geological Survey, and a U.S. electrical utility's database of power outages from 2002 to 2004. Our intersectional approach identifies a factor variable of American Indian disadvantage as a correlate of average outage duration suggesting possible support for an institutional bias hypothesis. However, spatial error regression models demonstrate that unequal resilience within our study area is most consistently explained by proximity to priority assets (i.e., hospitals), average downstream customers affected by outages, and environmental conditions (i.e., the seasonality of outages). These results are consistent with existing research on utilities' response to power outages, and more broadly with the bureaucratic decision rules perspective on service inequalities. We discuss the implications of our findings for future research and energy policy.