Researchers measuring racial inequality of neighborhood environment across metropolitan areas (MAs) have traditionally employed segregation measures, yet such measures are limited for incorporating a third axis of information, including neighborhood opportunity. Using Census 2000 tract-level data for the largest U.S. MAs, we introduce the interquartile-range overlap statistic to summarize the substantial separation of entire distributions of neighborhood environments between racial groups. We find neighborhood poverty distributions for minorities overlap only 27% with those for whites. Further, the separation of racial groups into neighborhoods of differing poverty rates is strongly correlated with racial residential segregation. The overlap statistic provides a straightforward, policy-relevant metric for monitoring progress towards achieving more equal environments of neighborhood opportunity space.