Unemployment Rate in Petroleum County, MT was 4.10% in March of 2024, according to the United States Federal Reserve. Historically, Unemployment Rate in Petroleum County, MT reached a record high of 11.90 in January of 1991 and a record low of 0.70 in May of 1990. Trading Economics provides the current actual value, an historical data chart and related indicators for Unemployment Rate in Petroleum County, MT - last updated from the United States Federal Reserve on May of 2024.