Income Inequality in Petroleum County, MT was 8.14347 Ratio in January of 2022, according to the United States Federal Reserve. Historically, Income Inequality in Petroleum County, MT reached a record high of 11.91613 in January of 2013 and a record low of 8.14347 in January of 2022. Trading Economics provides the current actual value, an historical data chart and related indicators for Income Inequality in Petroleum County, MT - last updated from the United States Federal Reserve on May of 2024.