There are 3 US Post Offices in Meagher County serving a total of 2,051 residents equating to 684 residents per post office. It's estimated that approximately 3,274 packages are handled across the 3 county post offices annually. Meagher County (pronounced Marr) is a county located in the U.S. state of Montana. As of the 2010 census, the population was 1,891. Its county seat is White Sulphur Springs. According to the U.S. Census Bureau, the 2010 center of population of Montana is located in Meagher County at 46.78\u00b0N 111.3\u00b0W\ufeff / 46.78; -111.3"