St. Louis is a city in Central Michigan, and is the second largest population center of Gratiot County, with 4,494 residents. St. Louis is famous for being the "Geographic Center of Michigan's Lower Peninsula." Its small-town atmosphere is ideal for people who are looking for safe neighborhoods and easy driving, yet its active community organizations still provide a vibrant calendar of events for people who enjoy live music and other forms of entertainment. St. Louis' historic downtown district is located on Business US-127, along the "Old 27 Route."