There are 8 US Post Offices in Montgomery County serving a total of 13,253 residents equating to 1,657 residents per post office. It's estimated that approximately 21,153 packages are handled across the 8 county post offices annually. Montgomery County is a county located in the eastern portion of the U.S. state of Missouri. As of the 2010 census, the population was 12,236. Its county seat is Montgomery City. The county was named in honor of Richard Montgomery, an American Revolutionary War general killed in 1775 while attempting to capture Quebec City, Canada. With a branch of Stone Hill Winery in New Florence, the county is part of the Missouri Rhineland. It is located approximately halfway between Columbia and St. Louis."