Libby is a city in northwestern Montana, United States and the county seat of Lincoln County. The population was 2,775 at the 2020 census. Lib…Libby is a city in northwestern Montana, United States and the county seat of Lincoln County. The population was 2,775 at the 2020 census. Libby suffered from the area's contamination from nearby vermiculite mines contaminated with particularly fragile asbestos, leading to the town's inclusion in the United States Environmental Protection Agency's National Priorities List status in 2002 and Public Health Emergency event in 2009. Most risk was reduced by 2015.