White to Non-White Racial Dissimilarity (5-year estimate) Index for Lewis and Clark County, MT was 28.56% in January of 2022, according to the United States Federal Reserve. Historically, White to Non-White Racial Dissimilarity (5-year estimate) Index for Lewis and Clark County, MT reached a record high of 28.56 in January of 2022 and a record low of 16.38 in January of 2013. Trading Economics provides the current actual value, an historical data chart and related indicators for White to Non-White Racial Dissimilarity (5-year estimate) Index for Lewis and Clark County, MT - last updated from the United States Federal Reserve on May of 2024.