Petroleum County, Montana

Petroleum County
Petroleum County
County
	Petroleum County Courthouse in Winnett
	Location within the U.S. state of Montana
	Montana's location within the U.S.
	Coordinates: 47°07′N 108°16′W / 47.11°N 108.26°W
Country	United States
State	Montana
Founded	February 25, 1925
Named for	Petroleum fields
Seat	Winnett
Largest town	Winnett
Area
• Total	1,674 sq mi (4,340 km2)
• Land	1,655 sq mi (4,290 km2)
• Water	19 sq mi (50 km2) 1.1%
Population (2020)
• Total	496
• Estimate (2022)	524
• Density	0.30/sq mi (0.11/km2)
Time zone	UTC−7 (Mountain)
• Summer (DST)	UTC−6 (MDT)
Congressional district	2nd
Website	petroleumcountymt.org
	Montana county number 55;

Petroleum County is a county in the U.S. state of Montana. As of the 2020 census, the population was 496,^[1] making it the least populous county in Montana and the eighth-least populous in the United States.^[2] Its county seat is Winnett.^[3] The county's area was partitioned from Fergus County in 1925 to become the last of Montana's 56 counties to be organized.^[4]^[5]

^ "State & County QuickFacts". United States Census Bureau. Retrieved April 5, 2023.
^ "Top 10: Least Populous Counties, During the Period of 2005-2009". PolicyMap. February 28, 2011. Retrieved July 7, 2013.
^ "Find a County". National Association of Counties. Retrieved June 7, 2011.
^ Ellie Arguimbau; Ellen Baumler; Charlene L. Porsild; Brian Shovers (2009). Montana Place Names: From Alzada to Zortman. Montana Historical Society. p. 204. ISBN 978-0-9759196-1-3.
^ Soils Industry, pp. 1-2